<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2023 Workiva-->
<!--r:e9ae8f48-5eae-4dd2-92b4-80ce29f438ef,g:2d211e94-f778-4473-ae1e-1287863fdad7-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.federalrealty.com/role/DocumentandEntityInformationDocument" xlink:type="simple" xlink:href="frt-20230630.xsd#DocumentandEntityInformationDocument"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/DocumentandEntityInformationDocument" xlink:type="extended" id="ieee16eea61cc4ece9ba9cce08e0edb85_DocumentandEntityInformationDocument">
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_1f39437a-d4af-40a9-8e9d-3f77e1cc8fd0" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_DocumentType_1f39437a-d4af-40a9-8e9d-3f77e1cc8fd0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_efe8c2bf-b1d8-431d-94f4-6177aa1f90d6" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentQuarterlyReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_DocumentQuarterlyReport_efe8c2bf-b1d8-431d-94f4-6177aa1f90d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_d966fcf0-6040-4104-94d1-b9a69f760aac" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_DocumentPeriodEndDate_d966fcf0-6040-4104-94d1-b9a69f760aac" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_e7f6bb66-7637-42eb-b8b4-8434415af74a" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_DocumentTransitionReport_e7f6bb66-7637-42eb-b8b4-8434415af74a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_811f5dc9-14e8-4ce2-b8eb-ac0aa783f2ad" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityFileNumber_811f5dc9-14e8-4ce2-b8eb-ac0aa783f2ad" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_db0edf54-0dbf-4f09-8d8a-cdc955f429a2" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityRegistrantName_db0edf54-0dbf-4f09-8d8a-cdc955f429a2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_35fa056b-b075-4ddc-a958-e4e5145763b7" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityCentralIndexKey_35fa056b-b075-4ddc-a958-e4e5145763b7" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_f03479b5-a31d-4a5a-a454-3259d1b22116" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_CurrentFiscalYearEndDate_f03479b5-a31d-4a5a-a454-3259d1b22116" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_69499f5f-f18c-4d25-93e0-4edd55a56932" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_DocumentFiscalYearFocus_69499f5f-f18c-4d25-93e0-4edd55a56932" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_bef10da4-15f4-4773-9b46-05d537c29af9" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_DocumentFiscalPeriodFocus_bef10da4-15f4-4773-9b46-05d537c29af9" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_2396f48b-918f-4d00-9b34-a7c8c8764d0f" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_AmendmentFlag_2396f48b-918f-4d00-9b34-a7c8c8764d0f" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_4ee0cede-97d3-4e06-9f00-b8f5426670da" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityIncorporationStateCountryCode_4ee0cede-97d3-4e06-9f00-b8f5426670da" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_9a215772-5149-48b4-9b6b-418092633dfd" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityTaxIdentificationNumber_9a215772-5149-48b4-9b6b-418092633dfd" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_49fab6aa-0ebf-405d-b661-9dabe619d2b0" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityAddressAddressLine1_49fab6aa-0ebf-405d-b661-9dabe619d2b0" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_83448978-fe22-4437-b147-09f8ed3f79e0" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityAddressCityOrTown_83448978-fe22-4437-b147-09f8ed3f79e0" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_1f0f9e3c-4bbf-4561-8438-ef663496ed7c" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityAddressStateOrProvince_1f0f9e3c-4bbf-4561-8438-ef663496ed7c" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_eee048d3-55d3-4158-b716-40332b3dba7c" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityAddressPostalZipCode_eee048d3-55d3-4158-b716-40332b3dba7c" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_5374975c-581d-4604-a406-4b57ce4efddb" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_CityAreaCode_5374975c-581d-4604-a406-4b57ce4efddb" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_12f5c2d3-002d-472b-b68f-c0bfe45f19b9" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_LocalPhoneNumber_12f5c2d3-002d-472b-b68f-c0bfe45f19b9" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_36b1f5bd-394a-4cc1-a1af-02092e3b6cf1" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_Security12bTitle_36b1f5bd-394a-4cc1-a1af-02092e3b6cf1" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_86f91bc6-b603-409d-a2e3-d70ba3615848" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_TradingSymbol_86f91bc6-b603-409d-a2e3-d70ba3615848" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_1bf32d10-150e-4aa7-a555-0bd7984b8c20" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_SecurityExchangeName_1bf32d10-150e-4aa7-a555-0bd7984b8c20" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_609358d4-44d1-4429-b2bf-8b073be03ade" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityCurrentReportingStatus_609358d4-44d1-4429-b2bf-8b073be03ade" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_009082c5-5470-4789-bb59-c937d3d2aef0" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityInteractiveDataCurrent_009082c5-5470-4789-bb59-c937d3d2aef0" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_5791f13f-26cf-4e1a-b253-c3ae00eb6ebb" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityFilerCategory_5791f13f-26cf-4e1a-b253-c3ae00eb6ebb" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_99154df4-01b5-4a0b-8fd9-16c9bb96c1d1" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntitySmallBusiness_99154df4-01b5-4a0b-8fd9-16c9bb96c1d1" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_88042946-63aa-4d5d-8689-3a7ae6e4c4db" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityEmergingGrowthCompany_88042946-63aa-4d5d-8689-3a7ae6e4c4db" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_f938c5fc-1d95-41c2-b38d-8e5bb35c29c5" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityShellCompany_f938c5fc-1d95-41c2-b38d-8e5bb35c29c5" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_196fc38f-dc05-4803-99b0-732c5720406a" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_196fc38f-dc05-4803-99b0-732c5720406a" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitiesTable_ccb0c67d-b797-4198-b717-c2da98d68c7e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_EntityInformationLineItems_26b2c357-518e-4057-82f0-901c890bd3e6" xlink:to="loc_dei_EntitiesTable_ccb0c67d-b797-4198-b717-c2da98d68c7e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityListingsExchangeAxis_03fcba8a-fc02-4987-8cb5-e6747c61d8f9" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityListingsExchangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_ccb0c67d-b797-4198-b717-c2da98d68c7e" xlink:to="loc_dei_EntityListingsExchangeAxis_03fcba8a-fc02-4987-8cb5-e6747c61d8f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_ExchangeDomain_03fcba8a-fc02-4987-8cb5-e6747c61d8f9_default" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_ExchangeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_EntityListingsExchangeAxis_03fcba8a-fc02-4987-8cb5-e6747c61d8f9" xlink:to="loc_dei_ExchangeDomain_03fcba8a-fc02-4987-8cb5-e6747c61d8f9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_ExchangeDomain_e2ed5c74-29fe-43b2-a888-30fc84157c62" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_ExchangeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_EntityListingsExchangeAxis_03fcba8a-fc02-4987-8cb5-e6747c61d8f9" xlink:to="loc_dei_ExchangeDomain_e2ed5c74-29fe-43b2-a888-30fc84157c62" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_exch_XNYS_7ddb511e-da7e-427a-9dad-e959af4b1c65" xlink:href="https://xbrl.sec.gov/exch/2023/exch-2023.xsd#exch_XNYS"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_ExchangeDomain_e2ed5c74-29fe-43b2-a888-30fc84157c62" xlink:to="loc_exch_XNYS_7ddb511e-da7e-427a-9dad-e959af4b1c65" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_f7a2acd2-e828-4898-a229-c74a2f396fd6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_ccb0c67d-b797-4198-b717-c2da98d68c7e" xlink:to="loc_us-gaap_StatementClassOfStockAxis_f7a2acd2-e828-4898-a229-c74a2f396fd6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_f7a2acd2-e828-4898-a229-c74a2f396fd6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_f7a2acd2-e828-4898-a229-c74a2f396fd6" xlink:to="loc_us-gaap_ClassOfStockDomain_f7a2acd2-e828-4898-a229-c74a2f396fd6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_17ca090a-cc91-45bb-b2dc-64beedc3abc8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_f7a2acd2-e828-4898-a229-c74a2f396fd6" xlink:to="loc_us-gaap_ClassOfStockDomain_17ca090a-cc91-45bb-b2dc-64beedc3abc8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_1f595faf-e220-4b75-907b-81c3e4010820" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_17ca090a-cc91-45bb-b2dc-64beedc3abc8" xlink:to="loc_us-gaap_CommonStockMember_1f595faf-e220-4b75-907b-81c3e4010820" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_DepositarySharesMember_5c6360f9-1acf-42e3-8569-90c376ae6e56" xlink:href="frt-20230630.xsd#frt_DepositarySharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_17ca090a-cc91-45bb-b2dc-64beedc3abc8" xlink:to="loc_frt_DepositarySharesMember_5c6360f9-1acf-42e3-8569-90c376ae6e56" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_04f519ab-1633-49a0-a2e0-7f1a0b07c190" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_ccb0c67d-b797-4198-b717-c2da98d68c7e" xlink:to="loc_dei_LegalEntityAxis_04f519ab-1633-49a0-a2e0-7f1a0b07c190" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_04f519ab-1633-49a0-a2e0-7f1a0b07c190_default" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_04f519ab-1633-49a0-a2e0-7f1a0b07c190" xlink:to="loc_dei_EntityDomain_04f519ab-1633-49a0-a2e0-7f1a0b07c190_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_8a85da02-9d8e-4181-8059-20f4c5d851b3" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_04f519ab-1633-49a0-a2e0-7f1a0b07c190" xlink:to="loc_dei_EntityDomain_8a85da02-9d8e-4181-8059-20f4c5d851b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_FederalRealtyOPLPMember_737be37b-ad16-47b4-b3ef-cb8858bc75e1" xlink:href="frt-20230630.xsd#frt_FederalRealtyOPLPMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_8a85da02-9d8e-4181-8059-20f4c5d851b3" xlink:to="loc_frt_FederalRealtyOPLPMember_737be37b-ad16-47b4-b3ef-cb8858bc75e1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/ConsolidatedBalanceSheets" xlink:type="simple" xlink:href="frt-20230630.xsd#ConsolidatedBalanceSheets"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ConsolidatedBalanceSheets" xlink:type="extended" id="iea926f7d7c834522a5a68fe0f670224a_ConsolidatedBalanceSheets">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_91a93439-41ec-4144-bd86-883577bfb4d2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_91a93439-41ec-4144-bd86-883577bfb4d2" xlink:to="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RentalProperties_c7d6a801-a608-4fde-87f7-3c87c01ba847" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RentalProperties"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:to="loc_us-gaap_RentalProperties_c7d6a801-a608-4fde-87f7-3c87c01ba847" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressGross_a2fab57a-9716-43cf-9f02-d9e3d6649acb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConstructionInProgressGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:to="loc_us-gaap_ConstructionInProgressGross_a2fab57a-9716-43cf-9f02-d9e3d6649acb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateInvestmentPropertyAtCost_a541008d-6e81-4fb5-aea3-4aae0a83f4ae" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RealEstateInvestmentPropertyAtCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:to="loc_us-gaap_RealEstateInvestmentPropertyAtCost_a541008d-6e81-4fb5-aea3-4aae0a83f4ae" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation_e19c5358-b0e7-4429-9c4f-a25d3d7c3d26" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:to="loc_us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation_e19c5358-b0e7-4429-9c4f-a25d3d7c3d26" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateInvestmentPropertyNet_47699dec-5f77-4b74-8012-53426b2cf516" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RealEstateInvestmentPropertyNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:to="loc_us-gaap_RealEstateInvestmentPropertyNet_47699dec-5f77-4b74-8012-53426b2cf516" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_80780a20-0b9c-434d-b213-50eb7b37a963" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_80780a20-0b9c-434d-b213-50eb7b37a963" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsAndNotesReceivableNet_2f25d8f8-f312-4f6b-91fe-aef98f8accb1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsAndNotesReceivableNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:to="loc_us-gaap_AccountsAndNotesReceivableNet_2f25d8f8-f312-4f6b-91fe-aef98f8accb1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MortgageLoansOnRealEstateCommercialAndConsumerNet_83c0d84b-2576-4b46-bede-87f0df91a2eb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MortgageLoansOnRealEstateCommercialAndConsumerNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:to="loc_us-gaap_MortgageLoansOnRealEstateCommercialAndConsumerNet_83c0d84b-2576-4b46-bede-87f0df91a2eb" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures_6f2479c1-e02f-4b06-976e-46bf3cbca420" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:to="loc_us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures_6f2479c1-e02f-4b06-976e-46bf3cbca420" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_f94c8e7d-5e9c-4f7e-ba8e-723283a69dda" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_f94c8e7d-5e9c-4f7e-ba8e-723283a69dda" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAsset_eef632ca-eb30-473f-8873-579f1997b6d1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinanceLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:to="loc_us-gaap_FinanceLeaseRightOfUseAsset_eef632ca-eb30-473f-8873-579f1997b6d1" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssets_853d2cee-1d6b-4f67-817c-67ca697edac4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PrepaidExpenseAndOtherAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssets_853d2cee-1d6b-4f67-817c-67ca697edac4" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_7e0929d5-2581-4278-80e7-2133074513ad" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fcc229f6-abfc-42a1-8c14-f8f0198741c5" xlink:to="loc_us-gaap_Assets_7e0929d5-2581-4278-80e7-2133074513ad" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract_5c64a4c6-c9c3-47e0-8038-54ba7e449389" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_91a93439-41ec-4144-bd86-883577bfb4d2" xlink:to="loc_us-gaap_LiabilitiesAbstract_5c64a4c6-c9c3-47e0-8038-54ba7e449389" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebt_cd35612d-c43d-47d5-807d-9315b6aa4440" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SecuredDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_5c64a4c6-c9c3-47e0-8038-54ba7e449389" xlink:to="loc_us-gaap_SecuredDebt_cd35612d-c43d-47d5-807d-9315b6aa4440" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayable_d499d2c1-4133-49bf-ba08-33ef6e8785f5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NotesPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_5c64a4c6-c9c3-47e0-8038-54ba7e449389" xlink:to="loc_us-gaap_NotesPayable_d499d2c1-4133-49bf-ba08-33ef6e8785f5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebt_9e930327-57f7-4594-9fa6-8f1105e622de" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_UnsecuredDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_5c64a4c6-c9c3-47e0-8038-54ba7e449389" xlink:to="loc_us-gaap_UnsecuredDebt_9e930327-57f7-4594-9fa6-8f1105e622de" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent_e2abd994-4aa4-4e9f-aa91-cab2b8961468" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_5c64a4c6-c9c3-47e0-8038-54ba7e449389" xlink:to="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent_e2abd994-4aa4-4e9f-aa91-cab2b8961468" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableCurrentAndNoncurrent_7dd37c49-bd21-4f77-b6a0-9de82b207546" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DividendsPayableCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_5c64a4c6-c9c3-47e0-8038-54ba7e449389" xlink:to="loc_us-gaap_DividendsPayableCurrentAndNoncurrent_7dd37c49-bd21-4f77-b6a0-9de82b207546" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecurityDepositLiability_a00de059-99b3-4a27-8b1d-46095e86cf9e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SecurityDepositLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_5c64a4c6-c9c3-47e0-8038-54ba7e449389" xlink:to="loc_us-gaap_SecurityDepositLiability_a00de059-99b3-4a27-8b1d-46095e86cf9e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_aed00434-8ad3-4069-94ed-ccb3bf239399" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_5c64a4c6-c9c3-47e0-8038-54ba7e449389" xlink:to="loc_us-gaap_OperatingLeaseLiability_aed00434-8ad3-4069-94ed-ccb3bf239399" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiability_f10f04c2-d66b-4e2d-85a5-6fa7e5b46d3a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinanceLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_5c64a4c6-c9c3-47e0-8038-54ba7e449389" xlink:to="loc_us-gaap_FinanceLeaseLiability_f10f04c2-d66b-4e2d-85a5-6fa7e5b46d3a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCreditsAndOtherLiabilities_83f4643d-5dfb-4e2b-afe4-76b18ff9532e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredCreditsAndOtherLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_5c64a4c6-c9c3-47e0-8038-54ba7e449389" xlink:to="loc_us-gaap_DeferredCreditsAndOtherLiabilities_83f4643d-5dfb-4e2b-afe4-76b18ff9532e" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_74fa172a-fe26-46d5-a236-408f071d898f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_5c64a4c6-c9c3-47e0-8038-54ba7e449389" xlink:to="loc_us-gaap_Liabilities_74fa172a-fe26-46d5-a236-408f071d898f" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_62bee34e-3f48-4679-a5d6-9e962b19ab4c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_91a93439-41ec-4144-bd86-883577bfb4d2" xlink:to="loc_us-gaap_CommitmentsAndContingencies_62bee34e-3f48-4679-a5d6-9e962b19ab4c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_e1efed3a-990f-4e4b-8ed8-ecdcf0b68c5e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_91a93439-41ec-4144-bd86-883577bfb4d2" xlink:to="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_e1efed3a-990f-4e4b-8ed8-ecdcf0b68c5e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_b23ed604-477d-4390-8189-9b5ab1227178" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_91a93439-41ec-4144-bd86-883577bfb4d2" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_b23ed604-477d-4390-8189-9b5ab1227178" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_fb3ae754-3591-4aab-893e-29ddbe44cc68" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_b23ed604-477d-4390-8189-9b5ab1227178" xlink:to="loc_us-gaap_PreferredStockValue_fb3ae754-3591-4aab-893e-29ddbe44cc68" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_87faff4b-e799-4fe5-98df-ede7e715fd30" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_b23ed604-477d-4390-8189-9b5ab1227178" xlink:to="loc_us-gaap_CommonStockValue_87faff4b-e799-4fe5-98df-ede7e715fd30" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_08fe6474-5def-4b4f-88b2-993020d472c2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_b23ed604-477d-4390-8189-9b5ab1227178" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_08fe6474-5def-4b4f-88b2-993020d472c2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDistributionsInExcessOfNetIncome_9dbffa94-5aba-4d1d-9e1a-612eb33dccd0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedDistributionsInExcessOfNetIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_b23ed604-477d-4390-8189-9b5ab1227178" xlink:to="loc_us-gaap_AccumulatedDistributionsInExcessOfNetIncome_9dbffa94-5aba-4d1d-9e1a-612eb33dccd0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_132e0616-e4d0-4e6d-bd8e-220b14e90f77" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_b23ed604-477d-4390-8189-9b5ab1227178" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_132e0616-e4d0-4e6d-bd8e-220b14e90f77" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_641f4f94-e518-4f49-ba75-f5120bf96e16" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_b23ed604-477d-4390-8189-9b5ab1227178" xlink:to="loc_us-gaap_StockholdersEquity_641f4f94-e518-4f49-ba75-f5120bf96e16" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest_2d1f4b51-0817-4e77-80ed-2997e2bbd3bb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_b23ed604-477d-4390-8189-9b5ab1227178" xlink:to="loc_us-gaap_MinorityInterest_2d1f4b51-0817-4e77-80ed-2997e2bbd3bb" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_442629fc-406a-4b29-8060-aefddd9230e0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_b23ed604-477d-4390-8189-9b5ab1227178" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_442629fc-406a-4b29-8060-aefddd9230e0" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalAbstract_517c9c95-17bb-4fed-908c-5b1ccc51da98" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_91a93439-41ec-4144-bd86-883577bfb4d2" xlink:to="loc_us-gaap_PartnersCapitalAbstract_517c9c95-17bb-4fed-908c-5b1ccc51da98" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredUnitsPreferredPartnersCapitalAccounts_26df831f-0075-4c35-8963-51bb3b5bd683" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredUnitsPreferredPartnersCapitalAccounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PartnersCapitalAbstract_517c9c95-17bb-4fed-908c-5b1ccc51da98" xlink:to="loc_us-gaap_PreferredUnitsPreferredPartnersCapitalAccounts_26df831f-0075-4c35-8963-51bb3b5bd683" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_CommonUnitsCapitalAccounts_272525b4-b52d-4500-a564-ad14452281a8" xlink:href="frt-20230630.xsd#frt_CommonUnitsCapitalAccounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PartnersCapitalAbstract_517c9c95-17bb-4fed-908c-5b1ccc51da98" xlink:to="loc_frt_CommonUnitsCapitalAccounts_272525b4-b52d-4500-a564-ad14452281a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_ff5827bc-c617-41bf-8130-7144c3c1547c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapital_47cd3917-b1c4-4493-8b77-56d6ddc01dc3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PartnersCapitalAbstract_517c9c95-17bb-4fed-908c-5b1ccc51da98" xlink:to="loc_us-gaap_PartnersCapital_47cd3917-b1c4-4493-8b77-56d6ddc01dc3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalAttributableToNoncontrollingInterest_95d1c562-3c4d-4d84-962a-63f87df0c743" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PartnersCapitalAbstract_517c9c95-17bb-4fed-908c-5b1ccc51da98" xlink:to="loc_us-gaap_PartnersCapitalAttributableToNoncontrollingInterest_95d1c562-3c4d-4d84-962a-63f87df0c743" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest_44bf0ee4-263c-4210-b852-b920cae3a884" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PartnersCapitalAbstract_517c9c95-17bb-4fed-908c-5b1ccc51da98" xlink:to="loc_us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest_44bf0ee4-263c-4210-b852-b920cae3a884" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_fb916bb5-e4ee-4001-8258-23ba54b64785" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_91a93439-41ec-4144-bd86-883577bfb4d2" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_fb916bb5-e4ee-4001-8258-23ba54b64785" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_0e0bd978-ba25-4522-bee6-6f32745404de" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_91a93439-41ec-4144-bd86-883577bfb4d2" xlink:to="loc_us-gaap_StatementTable_0e0bd978-ba25-4522-bee6-6f32745404de" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_7f7e3d09-f9ea-4461-bc1a-117efa7a78ef" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_0e0bd978-ba25-4522-bee6-6f32745404de" xlink:to="loc_us-gaap_StatementClassOfStockAxis_7f7e3d09-f9ea-4461-bc1a-117efa7a78ef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_7f7e3d09-f9ea-4461-bc1a-117efa7a78ef_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_7f7e3d09-f9ea-4461-bc1a-117efa7a78ef" xlink:to="loc_us-gaap_ClassOfStockDomain_7f7e3d09-f9ea-4461-bc1a-117efa7a78ef_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_80c4d903-b7e4-4fdf-bf48-38588ad5bb3c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_7f7e3d09-f9ea-4461-bc1a-117efa7a78ef" xlink:to="loc_us-gaap_ClassOfStockDomain_80c4d903-b7e4-4fdf-bf48-38588ad5bb3c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_A5.0SeriesCCumulativeRedeemablePreferredMember_c634df06-49e4-48b3-86b5-0f9707e84d17" xlink:href="frt-20230630.xsd#frt_A5.0SeriesCCumulativeRedeemablePreferredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_80c4d903-b7e4-4fdf-bf48-38588ad5bb3c" xlink:to="loc_frt_A5.0SeriesCCumulativeRedeemablePreferredMember_c634df06-49e4-48b3-86b5-0f9707e84d17" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_A5417Series1CumulativeConvertiblePreferredMember_8893829f-8779-4f74-8c44-f8893891bbb4" xlink:href="frt-20230630.xsd#frt_A5417Series1CumulativeConvertiblePreferredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_80c4d903-b7e4-4fdf-bf48-38588ad5bb3c" xlink:to="loc_frt_A5417Series1CumulativeConvertiblePreferredMember_8893829f-8779-4f74-8c44-f8893891bbb4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_15759b66-130e-47e8-bc95-bf0567340765" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_0e0bd978-ba25-4522-bee6-6f32745404de" xlink:to="loc_srt_ConsolidatedEntitiesAxis_15759b66-130e-47e8-bc95-bf0567340765" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_15759b66-130e-47e8-bc95-bf0567340765_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_15759b66-130e-47e8-bc95-bf0567340765" xlink:to="loc_srt_ConsolidatedEntitiesDomain_15759b66-130e-47e8-bc95-bf0567340765_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_f40fa6e4-4fcc-4fcd-a275-dba140330103" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_15759b66-130e-47e8-bc95-bf0567340765" xlink:to="loc_srt_ConsolidatedEntitiesDomain_f40fa6e4-4fcc-4fcd-a275-dba140330103" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_PartnershipInterestMember_00f8df5b-386d-461a-be5d-c041f695cfbb" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_PartnershipInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_f40fa6e4-4fcc-4fcd-a275-dba140330103" xlink:to="loc_srt_PartnershipInterestMember_00f8df5b-386d-461a-be5d-c041f695cfbb" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/ConsolidatedBalanceSheetsParentheticals" xlink:type="simple" xlink:href="frt-20230630.xsd#ConsolidatedBalanceSheetsParentheticals"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ConsolidatedBalanceSheetsParentheticals" xlink:type="extended" id="i8ed57c7f7dec4959a4df46d112382524_ConsolidatedBalanceSheetsParentheticals">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_OperatingRealEstateFromConsolidatedVariableInterestEntities_d2e79eb4-6c2d-4a0c-9455-847c169ba035" xlink:href="frt-20230630.xsd#frt_OperatingRealEstateFromConsolidatedVariableInterestEntities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_frt_OperatingRealEstateFromConsolidatedVariableInterestEntities_d2e79eb4-6c2d-4a0c-9455-847c169ba035" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_Constructioninprogresofconsolidatedvariableieestentity_efc1f775-9170-4b43-b61b-5a1fed18a596" xlink:href="frt-20230630.xsd#frt_Constructioninprogresofconsolidatedvariableieestentity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_frt_Constructioninprogresofconsolidatedvariableieestentity_efc1f775-9170-4b43-b61b-5a1fed18a596" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_AccumulatedDepreciationAndAmortizationConsolidatedVariableInterestEntities_80e1d95f-9732-4fa5-aa80-6586d6dbb0b8" xlink:href="frt-20230630.xsd#frt_AccumulatedDepreciationAndAmortizationConsolidatedVariableInterestEntities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_frt_AccumulatedDepreciationAndAmortizationConsolidatedVariableInterestEntities_80e1d95f-9732-4fa5-aa80-6586d6dbb0b8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_MortgagePayableFromConsolidatedVariableInterestEntities_c4609cc6-a15d-4894-b4c0-6328cbb32ea8" xlink:href="frt-20230630.xsd#frt_MortgagePayableFromConsolidatedVariableInterestEntities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_frt_MortgagePayableFromConsolidatedVariableInterestEntities_c4609cc6-a15d-4894-b4c0-6328cbb32ea8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_05b3eac5-4a3e-4558-855d-4aa987df4c4b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_05b3eac5-4a3e-4558-855d-4aa987df4c4b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_f11552fa-6d6a-451e-89a4-bed501a9a6c1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_f11552fa-6d6a-451e-89a4-bed501a9a6c1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendRatePercentage_b97aa454-8f45-479e-b42e-7d653c037b2d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockDividendRatePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_PreferredStockDividendRatePercentage_b97aa454-8f45-479e-b42e-7d653c037b2d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockLiquidationPreference_08836cd0-0e68-403b-b7bf-ddb60b57265f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockLiquidationPreference"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_PreferredStockLiquidationPreference_08836cd0-0e68-403b-b7bf-ddb60b57265f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_1c88df67-afb9-46af-a8e8-02dbffb95d5d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_PreferredStockSharesIssued_1c88df67-afb9-46af-a8e8-02dbffb95d5d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_f3f72679-6bef-4bec-a573-953acc98793c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_CommonStockSharesIssued_f3f72679-6bef-4bec-a573-953acc98793c" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_6d61fde8-b65c-4fe8-8b3b-4f63eb178f83" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_6d61fde8-b65c-4fe8-8b3b-4f63eb178f83" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_3f61b270-ac4c-4b57-9404-141942221c54" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_3f61b270-ac4c-4b57-9404-141942221c54" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_e2c9abc2-a86b-4ece-b3a0-5b064a266377" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_e2c9abc2-a86b-4ece-b3a0-5b064a266377" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_6de27ebb-75c9-42ea-b32e-890c45aded96" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_6de27ebb-75c9-42ea-b32e-890c45aded96" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredUnitsIssued_0a8f73e9-7b82-42fb-ba99-c2e965c457e4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredUnitsIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_PreferredUnitsIssued_0a8f73e9-7b82-42fb-ba99-c2e965c457e4" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredUnitsOutstanding_6a85a1ce-369e-4b29-8e91-5469291e3460" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredUnitsOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_PreferredUnitsOutstanding_6a85a1ce-369e-4b29-8e91-5469291e3460" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonUnitIssued_d55ba943-18b2-4e3f-83f6-bd641e2d9bca" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonUnitIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_CommonUnitIssued_d55ba943-18b2-4e3f-83f6-bd641e2d9bca" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonUnitOutstanding_9fb424f1-a515-4b0a-b501-3a86a5cb8a1d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonUnitOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_CommonUnitOutstanding_9fb424f1-a515-4b0a-b501-3a86a5cb8a1d" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_6bf61445-0e3f-4397-9caa-2b43980c4e88" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_b7edaa10-8bb9-46c6-ad4d-676f81151105" xlink:to="loc_us-gaap_StatementTable_6bf61445-0e3f-4397-9caa-2b43980c4e88" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_2c20b82a-5023-4894-ba59-3e6cc85e4ff2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_6bf61445-0e3f-4397-9caa-2b43980c4e88" xlink:to="loc_us-gaap_StatementClassOfStockAxis_2c20b82a-5023-4894-ba59-3e6cc85e4ff2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_2c20b82a-5023-4894-ba59-3e6cc85e4ff2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2c20b82a-5023-4894-ba59-3e6cc85e4ff2" xlink:to="loc_us-gaap_ClassOfStockDomain_2c20b82a-5023-4894-ba59-3e6cc85e4ff2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_1049f503-d11e-46b9-a425-0f061255d077" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2c20b82a-5023-4894-ba59-3e6cc85e4ff2" xlink:to="loc_us-gaap_ClassOfStockDomain_1049f503-d11e-46b9-a425-0f061255d077" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_A5.0SeriesCCumulativeRedeemablePreferredMember_3dc43a43-d401-4003-a534-ec2e1e94d1f4" xlink:href="frt-20230630.xsd#frt_A5.0SeriesCCumulativeRedeemablePreferredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_1049f503-d11e-46b9-a425-0f061255d077" xlink:to="loc_frt_A5.0SeriesCCumulativeRedeemablePreferredMember_3dc43a43-d401-4003-a534-ec2e1e94d1f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_A5417Series1CumulativeConvertiblePreferredMember_5a57f076-b26d-48b1-b231-d8117e7212cb" xlink:href="frt-20230630.xsd#frt_A5417Series1CumulativeConvertiblePreferredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_1049f503-d11e-46b9-a425-0f061255d077" xlink:to="loc_frt_A5417Series1CumulativeConvertiblePreferredMember_5a57f076-b26d-48b1-b231-d8117e7212cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_5c384d26-e98d-46e0-8408-4310c9c2aee3" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_6bf61445-0e3f-4397-9caa-2b43980c4e88" xlink:to="loc_srt_ConsolidatedEntitiesAxis_5c384d26-e98d-46e0-8408-4310c9c2aee3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_5c384d26-e98d-46e0-8408-4310c9c2aee3_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_5c384d26-e98d-46e0-8408-4310c9c2aee3" xlink:to="loc_srt_ConsolidatedEntitiesDomain_5c384d26-e98d-46e0-8408-4310c9c2aee3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_92fe06e8-6ef1-412a-b68a-b09e9da88f49" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_5c384d26-e98d-46e0-8408-4310c9c2aee3" xlink:to="loc_srt_ConsolidatedEntitiesDomain_92fe06e8-6ef1-412a-b68a-b09e9da88f49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_PartnershipInterestMember_f620a0cc-5154-4045-a25d-187392834ff1" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_PartnershipInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_92fe06e8-6ef1-412a-b68a-b09e9da88f49" xlink:to="loc_srt_PartnershipInterestMember_f620a0cc-5154-4045-a25d-187392834ff1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:type="simple" xlink:href="frt-20230630.xsd#ConsolidatedStatementsOfComprehensiveIncome"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:type="extended" id="i7a387b540e984058a555853ef772fb65_ConsolidatedStatementsOfComprehensiveIncome">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_d141d2b2-3935-4ae0-a960-653a29cbaa2f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_us-gaap_RevenuesAbstract_d141d2b2-3935-4ae0-a960-653a29cbaa2f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLeaseIncome_807d195d-8c28-42fc-99f5-4b1b7d01ba25" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLeaseIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_d141d2b2-3935-4ae0-a960-653a29cbaa2f" xlink:to="loc_us-gaap_OperatingLeaseLeaseIncome_807d195d-8c28-42fc-99f5-4b1b7d01ba25" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_RevenueMortgageInterest_b2c770cc-672b-4168-9471-268c1845800a" xlink:href="frt-20230630.xsd#frt_RevenueMortgageInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_d141d2b2-3935-4ae0-a960-653a29cbaa2f" xlink:to="loc_frt_RevenueMortgageInterest_b2c770cc-672b-4168-9471-268c1845800a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_19f431f8-e332-4c2b-8df7-4f2c8d5e4481" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_d141d2b2-3935-4ae0-a960-653a29cbaa2f" xlink:to="loc_us-gaap_Revenues_19f431f8-e332-4c2b-8df7-4f2c8d5e4481" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_81c0d999-1e02-4f59-9b06-921ef9d4b911" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_us-gaap_OperatingExpensesAbstract_81c0d999-1e02-4f59-9b06-921ef9d4b911" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCostAndExpenseOperating_a2473a57-9e2c-4b8e-b047-2161f3f1a733" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherCostAndExpenseOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_81c0d999-1e02-4f59-9b06-921ef9d4b911" xlink:to="loc_us-gaap_OtherCostAndExpenseOperating_a2473a57-9e2c-4b8e-b047-2161f3f1a733" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateTaxExpense_adbb4995-97c6-4587-a116-2d6103d7b0a7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RealEstateTaxExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_81c0d999-1e02-4f59-9b06-921ef9d4b911" xlink:to="loc_us-gaap_RealEstateTaxExpense_adbb4995-97c6-4587-a116-2d6103d7b0a7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_99e89406-4d8d-45c9-9296-4e0c1fccd17c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_81c0d999-1e02-4f59-9b06-921ef9d4b911" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_99e89406-4d8d-45c9-9296-4e0c1fccd17c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization_c07cb0d2-06b1-4910-9818-7bbafa0871a1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_81c0d999-1e02-4f59-9b06-921ef9d4b911" xlink:to="loc_us-gaap_DepreciationAndAmortization_c07cb0d2-06b1-4910-9818-7bbafa0871a1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_2b9c7e3f-3ee9-40d8-be83-cd8445b578e8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_81c0d999-1e02-4f59-9b06-921ef9d4b911" xlink:to="loc_us-gaap_OperatingExpenses_2b9c7e3f-3ee9-40d8-be83-cd8445b578e8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_GainOnSaleOfRealEstate_164015cf-0e6f-4459-b31a-b9f769f4234b" xlink:href="frt-20230630.xsd#frt_GainOnSaleOfRealEstate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_81c0d999-1e02-4f59-9b06-921ef9d4b911" xlink:to="loc_frt_GainOnSaleOfRealEstate_164015cf-0e6f-4459-b31a-b9f769f4234b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_38c1e1ac-fe59-41d4-b473-8c71ec5e25e3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_us-gaap_OperatingIncomeLoss_38c1e1ac-fe59-41d4-b473-8c71ec5e25e3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIncomeAndExpensesAbstract_d11bd0e5-b971-41cb-99a8-a09753bc8143" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherIncomeAndExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_us-gaap_OtherIncomeAndExpensesAbstract_d11bd0e5-b971-41cb-99a8-a09753bc8143" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeOther_e2e1a62a-277f-4936-b688-f619da35976e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestIncomeOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherIncomeAndExpensesAbstract_d11bd0e5-b971-41cb-99a8-a09753bc8143" xlink:to="loc_us-gaap_InterestIncomeOther_e2e1a62a-277f-4936-b688-f619da35976e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_7e91a593-a0ac-440f-8edf-2bd246b42247" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherIncomeAndExpensesAbstract_d11bd0e5-b971-41cb-99a8-a09753bc8143" xlink:to="loc_us-gaap_InterestExpense_7e91a593-a0ac-440f-8edf-2bd246b42247" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_21154a21-0ade-4c5e-85c8-86173f4e9482" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherIncomeAndExpensesAbstract_d11bd0e5-b971-41cb-99a8-a09753bc8143" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_21154a21-0ade-4c5e-85c8-86173f4e9482" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_e62b7739-04f9-44e8-9748-3c1449345311" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_us-gaap_ProfitLoss_e62b7739-04f9-44e8-9748-3c1449345311" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_8d06e86b-7e5e-4adc-95af-b26b1453b95d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_8d06e86b-7e5e-4adc-95af-b26b1453b95d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_ffc9c74a-ccc7-4087-8431-97311d643546" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_us-gaap_NetIncomeLoss_ffc9c74a-ccc7-4087-8431-97311d643546" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_d7135a64-91fd-4feb-8c9d-ecb056c443c1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_d7135a64-91fd-4feb-8c9d-ecb056c443c1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_DistributionsDeclaredToPreferredUnitHolders_a9bb1a37-9a16-495b-90c5-0ff1b1bac65f" xlink:href="frt-20230630.xsd#frt_DistributionsDeclaredToPreferredUnitHolders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_frt_DistributionsDeclaredToPreferredUnitHolders_a9bb1a37-9a16-495b-90c5-0ff1b1bac65f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_4e88e35e-6ab0-4481-bd2f-1c8901b28379" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_4e88e35e-6ab0-4481-bd2f-1c8901b28379" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAllocatedToGeneralPartners_35c85718-0011-4e19-9d64-49d3012f8377" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAllocatedToGeneralPartners"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_us-gaap_NetIncomeLossAllocatedToGeneralPartners_35c85718-0011-4e19-9d64-49d3012f8377" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicAbstract_5ae2880e-3bee-4983-a314-5854a663ed46" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareBasicAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_us-gaap_EarningsPerShareBasicAbstract_5ae2880e-3bee-4983-a314-5854a663ed46" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_c01ab5c7-1c17-47f2-87fc-71ec8cf14095" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_5ae2880e-3bee-4983-a314-5854a663ed46" xlink:to="loc_us-gaap_EarningsPerShareBasic_c01ab5c7-1c17-47f2-87fc-71ec8cf14095" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_31a089e1-ae05-4a31-b468-562aefa2de00" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_5ae2880e-3bee-4983-a314-5854a663ed46" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_31a089e1-ae05-4a31-b468-562aefa2de00" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDilutedAbstract_fb793721-15e8-4d0c-92c1-aad5cf2478d9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareDilutedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_us-gaap_EarningsPerShareDilutedAbstract_fb793721-15e8-4d0c-92c1-aad5cf2478d9" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_d7d8e113-e93e-4582-ba11-f8d5cfc60d80" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_fb793721-15e8-4d0c-92c1-aad5cf2478d9" xlink:to="loc_us-gaap_EarningsPerShareDiluted_d7d8e113-e93e-4582-ba11-f8d5cfc60d80" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_bab73ec1-7c55-499a-bb4b-c37c0b9b41e4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_fb793721-15e8-4d0c-92c1-aad5cf2478d9" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_bab73ec1-7c55-499a-bb4b-c37c0b9b41e4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_EARNINGSPERCOMMONUNITBASICAbstract_b768ab49-0084-4c5f-aaca-b53e47434d92" xlink:href="frt-20230630.xsd#frt_EARNINGSPERCOMMONUNITBASICAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_frt_EARNINGSPERCOMMONUNITBASICAbstract_b768ab49-0084-4c5f-aaca-b53e47434d92" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsPerOutstandingGeneralPartnershipUnitNetOfTax_bda90092-35fa-4e62-9e7e-7a94799afba5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossFromContinuingOperationsPerOutstandingGeneralPartnershipUnitNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_EARNINGSPERCOMMONUNITBASICAbstract_b768ab49-0084-4c5f-aaca-b53e47434d92" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsPerOutstandingGeneralPartnershipUnitNetOfTax_bda90092-35fa-4e62-9e7e-7a94799afba5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageLimitedPartnershipAndGeneralPartnershipUnitsOutstandingBasic_e912c942-8ab2-4d90-bad2-090b318424c7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageLimitedPartnershipAndGeneralPartnershipUnitsOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_EARNINGSPERCOMMONUNITBASICAbstract_b768ab49-0084-4c5f-aaca-b53e47434d92" xlink:to="loc_us-gaap_WeightedAverageLimitedPartnershipAndGeneralPartnershipUnitsOutstandingBasic_e912c942-8ab2-4d90-bad2-090b318424c7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_EARNINGSPERCOMMONUNITDILUTEDAbstract_4885dd05-a56e-49f6-a147-08f6419d36e2" xlink:href="frt-20230630.xsd#frt_EARNINGSPERCOMMONUNITDILUTEDAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_frt_EARNINGSPERCOMMONUNITDILUTEDAbstract_4885dd05-a56e-49f6-a147-08f6419d36e2" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_NetIncomeAvailableForCommonUnitHoldersDiluted_df494ba7-f38c-4e6d-af84-0a138fdb91af" xlink:href="frt-20230630.xsd#frt_NetIncomeAvailableForCommonUnitHoldersDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_EARNINGSPERCOMMONUNITDILUTEDAbstract_4885dd05-a56e-49f6-a147-08f6419d36e2" xlink:to="loc_frt_NetIncomeAvailableForCommonUnitHoldersDiluted_df494ba7-f38c-4e6d-af84-0a138fdb91af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_WeightedAverageCommonUnitsOutstandingDiluted_c217e3d6-753e-4dd7-a5ea-c59545f1d20a" xlink:href="frt-20230630.xsd#frt_WeightedAverageCommonUnitsOutstandingDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_EARNINGSPERCOMMONUNITDILUTEDAbstract_4885dd05-a56e-49f6-a147-08f6419d36e2" xlink:to="loc_frt_WeightedAverageCommonUnitsOutstandingDiluted_c217e3d6-753e-4dd7-a5ea-c59545f1d20a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_82b24a6b-e568-4efc-8377-c527de2a497c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_82b24a6b-e568-4efc-8377-c527de2a497c" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_2a00bc01-30cf-4020-a445-5dc9cb69a34f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_82b24a6b-e568-4efc-8377-c527de2a497c" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_2a00bc01-30cf-4020-a445-5dc9cb69a34f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_bc5a4289-11d5-49fb-bf71-f13ec34136e3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_82b24a6b-e568-4efc-8377-c527de2a497c" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_bc5a4289-11d5-49fb-bf71-f13ec34136e3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_8dbfc811-ca2a-4dc0-be5d-fdd41c6b85fe" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_4a21d08c-cd7c-44db-b486-bf603586a4aa" xlink:to="loc_us-gaap_StatementTable_8dbfc811-ca2a-4dc0-be5d-fdd41c6b85fe" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_6d2e696d-8a6a-4799-86b0-c6b5bc83bb90" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_8dbfc811-ca2a-4dc0-be5d-fdd41c6b85fe" xlink:to="loc_srt_ConsolidatedEntitiesAxis_6d2e696d-8a6a-4799-86b0-c6b5bc83bb90" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_6d2e696d-8a6a-4799-86b0-c6b5bc83bb90_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_6d2e696d-8a6a-4799-86b0-c6b5bc83bb90" xlink:to="loc_srt_ConsolidatedEntitiesDomain_6d2e696d-8a6a-4799-86b0-c6b5bc83bb90_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_e75df0f8-e9b7-4cea-97e9-4874f4262de5" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_6d2e696d-8a6a-4799-86b0-c6b5bc83bb90" xlink:to="loc_srt_ConsolidatedEntitiesDomain_e75df0f8-e9b7-4cea-97e9-4874f4262de5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_PartnershipInterestMember_31bb4c3b-c2c1-49b0-9322-1ef4bdc97904" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_PartnershipInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_e75df0f8-e9b7-4cea-97e9-4874f4262de5" xlink:to="loc_srt_PartnershipInterestMember_31bb4c3b-c2c1-49b0-9322-1ef4bdc97904" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/ConsolidatedStatementOfShareholdersEquity" xlink:type="simple" xlink:href="frt-20230630.xsd#ConsolidatedStatementOfShareholdersEquity"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ConsolidatedStatementOfShareholdersEquity" xlink:type="extended" id="if18375e0dd58484396f80a1dcbbcec66_ConsolidatedStatementOfShareholdersEquity">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_a84c8505-6339-411e-9334-e28997616650" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_a84c8505-6339-411e-9334-e28997616650" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_5b76d7b9-1a2c-428c-8734-8f085cf8cbf8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_SharesOutstanding_5b76d7b9-1a2c-428c-8734-8f085cf8cbf8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_689ca8cc-5ca5-41e9-a19e-08e5c4319aed" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_689ca8cc-5ca5-41e9-a19e-08e5c4319aed" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_7e9ec471-b993-4fd4-967c-6ed5bbf697cd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_7e9ec471-b993-4fd4-967c-6ed5bbf697cd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_OtherComprehensiveIncomeLossNetOfPortionAttributableToNoncontrollingInterest_ea35a545-f05f-41f1-a305-5497b68ad2eb" xlink:href="frt-20230630.xsd#frt_OtherComprehensiveIncomeLossNetOfPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_frt_OtherComprehensiveIncomeLossNetOfPortionAttributableToNoncontrollingInterest_ea35a545-f05f-41f1-a305-5497b68ad2eb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStockCash_471df783-a4a2-4961-bd0f-5a1f62a26816" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DividendsCommonStockCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_DividendsCommonStockCash_471df783-a4a2-4961-bd0f-5a1f62a26816" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPreferredStockCash_b6db1c55-ce20-4f34-88ba-e9502256f61c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DividendsPreferredStockCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_DividendsPreferredStockCash_b6db1c55-ce20-4f34-88ba-e9502256f61c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_e1d08b56-d2ef-49ff-a517-428439eb5815" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_e1d08b56-d2ef-49ff-a517-428439eb5815" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_8d2727ea-e8a0-4f65-9e82-2dc04950aac5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_8d2727ea-e8a0-4f65-9e82-2dc04950aac5" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_41abcbb8-7a4c-45a9-b886-23f2cbd2c6e9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_41abcbb8-7a4c-45a9-b886-23f2cbd2c6e9" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_a8a5df4c-5482-4fbc-a82b-07c6c036eef8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_a8a5df4c-5482-4fbc-a82b-07c6c036eef8" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_c7ae814c-d098-4da4-a83f-5afe1a9a5a70" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_c7ae814c-d098-4da4-a83f-5afe1a9a5a70" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ShareBasedCompensationExpenseNetShares_9a8cbac1-bba6-4722-beca-76e426ad4162" xlink:href="frt-20230630.xsd#frt_ShareBasedCompensationExpenseNetShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_frt_ShareBasedCompensationExpenseNetShares_9a8cbac1-bba6-4722-beca-76e426ad4162" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ShareBasedCompensationExpenseNetValue_3a4c52c6-dbe9-4c71-83ab-4dc760b7af42" xlink:href="frt-20230630.xsd#frt_ShareBasedCompensationExpenseNetValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_frt_ShareBasedCompensationExpenseNetValue_3a4c52c6-dbe9-4c71-83ab-4dc760b7af42" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_471b1e3b-bc0c-4f1f-aeeb-90d7f30d8a7a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_471b1e3b-bc0c-4f1f-aeeb-90d7f30d8a7a" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_53531852-de05-40cb-80e6-67f494e0ecf6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_53531852-de05-40cb-80e6-67f494e0ecf6" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockSharesConverted1_d809614d-44ee-4e0c-9763-0c5f25a2ae7e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConversionOfStockSharesConverted1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_ConversionOfStockSharesConverted1_d809614d-44ee-4e0c-9763-0c5f25a2ae7e" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockAmountConverted1_47cb1442-6fe7-4c8f-8634-2d430c593214" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConversionOfStockAmountConverted1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_ConversionOfStockAmountConverted1_47cb1442-6fe7-4c8f-8634-2d430c593214" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_ea93b926-c55a-48c3-9cad-dd71605768d3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_ea93b926-c55a-48c3-9cad-dd71605768d3" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_080a43db-1a13-4c29-af95-d0b505f98b52" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_080a43db-1a13-4c29-af95-d0b505f98b52" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits_94281493-7aa5-463f-b5cb-130228e426ea" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits_94281493-7aa5-463f-b5cb-130228e426ea" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueConversionOfUnits_e9c98d97-d97c-4fc7-add1-2330bc8838d9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueConversionOfUnits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueConversionOfUnits_e9c98d97-d97c-4fc7-add1-2330bc8838d9" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromRedemptions_e144dde0-459e-4e1e-aec2-f5843f414a2f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterestDecreaseFromRedemptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromRedemptions_e144dde0-459e-4e1e-aec2-f5843f414a2f" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_Contributionsfromnoncontrollinginterests_d7b0dfb5-511c-453d-859b-4c47128daaa2" xlink:href="frt-20230630.xsd#frt_Contributionsfromnoncontrollinginterests"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_frt_Contributionsfromnoncontrollinginterests_d7b0dfb5-511c-453d-859b-4c47128daaa2" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityOther_a4d476e4-d276-41b6-aa9c-e5d831262683" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_eb747163-0d1f-46ed-9d4b-1948d206e338" xlink:to="loc_us-gaap_StockholdersEquityOther_a4d476e4-d276-41b6-aa9c-e5d831262683" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_28b00351-342f-40c9-9a94-85067c7c871a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_966323a2-aa0e-4727-8b81-f0418daca503" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_4f53cebb-ab1d-4f18-a2d8-e82c3a04089a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_a84c8505-6339-411e-9334-e28997616650" xlink:to="loc_us-gaap_StatementTable_4f53cebb-ab1d-4f18-a2d8-e82c3a04089a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_93f60b7d-ae9b-40b4-bd9a-192b7b96f938" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_4f53cebb-ab1d-4f18-a2d8-e82c3a04089a" xlink:to="loc_us-gaap_StatementClassOfStockAxis_93f60b7d-ae9b-40b4-bd9a-192b7b96f938" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_93f60b7d-ae9b-40b4-bd9a-192b7b96f938_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_93f60b7d-ae9b-40b4-bd9a-192b7b96f938" xlink:to="loc_us-gaap_ClassOfStockDomain_93f60b7d-ae9b-40b4-bd9a-192b7b96f938_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_90455584-a313-4fac-9ee1-a526004b9123" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_93f60b7d-ae9b-40b4-bd9a-192b7b96f938" xlink:to="loc_us-gaap_ClassOfStockDomain_90455584-a313-4fac-9ee1-a526004b9123" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_8ce393d0-ec39-455e-973a-796d9315ed2c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_90455584-a313-4fac-9ee1-a526004b9123" xlink:to="loc_us-gaap_PreferredStockMember_8ce393d0-ec39-455e-973a-796d9315ed2c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_67a78661-2ee5-4b19-963f-639cc602b494" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_90455584-a313-4fac-9ee1-a526004b9123" xlink:to="loc_us-gaap_CommonStockMember_67a78661-2ee5-4b19-963f-639cc602b494" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_e71f34a9-9cec-4acb-9461-1e5f272863d7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_4f53cebb-ab1d-4f18-a2d8-e82c3a04089a" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_e71f34a9-9cec-4acb-9461-1e5f272863d7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_e71f34a9-9cec-4acb-9461-1e5f272863d7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_e71f34a9-9cec-4acb-9461-1e5f272863d7" xlink:to="loc_us-gaap_EquityComponentDomain_e71f34a9-9cec-4acb-9461-1e5f272863d7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_2a071bde-31bc-49c8-b0ab-64181501a0c7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_e71f34a9-9cec-4acb-9461-1e5f272863d7" xlink:to="loc_us-gaap_EquityComponentDomain_2a071bde-31bc-49c8-b0ab-64181501a0c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_c9e9969e-6195-4157-a969-9edeaf144c32" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_2a071bde-31bc-49c8-b0ab-64181501a0c7" xlink:to="loc_us-gaap_PreferredStockMember_c9e9969e-6195-4157-a969-9edeaf144c32" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_fa029863-1171-48dd-bb1f-bfccdfa4d318" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_2a071bde-31bc-49c8-b0ab-64181501a0c7" xlink:to="loc_us-gaap_CommonStockMember_fa029863-1171-48dd-bb1f-bfccdfa4d318" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_dd655077-17c8-4637-a8f0-bd1a74785fd9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_2a071bde-31bc-49c8-b0ab-64181501a0c7" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_dd655077-17c8-4637-a8f0-bd1a74785fd9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDistributionsInExcessOfNetIncomeMember_ffb65b21-8848-437f-bc7c-025af1ea497c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedDistributionsInExcessOfNetIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_2a071bde-31bc-49c8-b0ab-64181501a0c7" xlink:to="loc_us-gaap_AccumulatedDistributionsInExcessOfNetIncomeMember_ffb65b21-8848-437f-bc7c-025af1ea497c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_25e6e569-4d76-443a-879b-125a6a7fab07" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_2a071bde-31bc-49c8-b0ab-64181501a0c7" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_25e6e569-4d76-443a-879b-125a6a7fab07" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_bcac0c39-489e-4054-8870-26a9fe5a4869" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_2a071bde-31bc-49c8-b0ab-64181501a0c7" xlink:to="loc_us-gaap_NoncontrollingInterestMember_bcac0c39-489e-4054-8870-26a9fe5a4869" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ConvertibleUnitTypeAxis_28833781-569e-4436-8032-84bc66706a01" xlink:href="frt-20230630.xsd#frt_ConvertibleUnitTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_4f53cebb-ab1d-4f18-a2d8-e82c3a04089a" xlink:to="loc_frt_ConvertibleUnitTypeAxis_28833781-569e-4436-8032-84bc66706a01" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ConvertibleUnitTypeDomain_28833781-569e-4436-8032-84bc66706a01_default" xlink:href="frt-20230630.xsd#frt_ConvertibleUnitTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_frt_ConvertibleUnitTypeAxis_28833781-569e-4436-8032-84bc66706a01" xlink:to="loc_frt_ConvertibleUnitTypeDomain_28833781-569e-4436-8032-84bc66706a01_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ConvertibleUnitTypeDomain_26374f0c-9dc9-4e41-a242-166c2e783253" xlink:href="frt-20230630.xsd#frt_ConvertibleUnitTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_frt_ConvertibleUnitTypeAxis_28833781-569e-4436-8032-84bc66706a01" xlink:to="loc_frt_ConvertibleUnitTypeDomain_26374f0c-9dc9-4e41-a242-166c2e783253" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_DownREITOPUnitsMember_4006de6b-67a4-427c-92f7-ee794636968f" xlink:href="frt-20230630.xsd#frt_DownREITOPUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_ConvertibleUnitTypeDomain_26374f0c-9dc9-4e41-a242-166c2e783253" xlink:to="loc_frt_DownREITOPUnitsMember_4006de6b-67a4-427c-92f7-ee794636968f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_A5417Series1CumulativeConvertiblePreferredMember_5049458d-568e-4ab5-b097-caa39e47c5fe" xlink:href="frt-20230630.xsd#frt_A5417Series1CumulativeConvertiblePreferredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_ConvertibleUnitTypeDomain_26374f0c-9dc9-4e41-a242-166c2e783253" xlink:to="loc_frt_A5417Series1CumulativeConvertiblePreferredMember_5049458d-568e-4ab5-b097-caa39e47c5fe" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/ConsolidatedStatementsOfCashFlows" xlink:type="simple" xlink:href="frt-20230630.xsd#ConsolidatedStatementsOfCashFlows"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ConsolidatedStatementsOfCashFlows" xlink:type="extended" id="ic3b6c2be84f94ed4a1e8f96040ff530d_ConsolidatedStatementsOfCashFlows">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_2cc52e5b-4276-47d7-b771-fb518bc3ba4e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_d0db76a6-9881-4dd7-b1d4-e7e322a41bb3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2cc52e5b-4276-47d7-b771-fb518bc3ba4e" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_d0db76a6-9881-4dd7-b1d4-e7e322a41bb3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_3c8db803-1c24-4969-9cb4-c591cbe7a397" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_d0db76a6-9881-4dd7-b1d4-e7e322a41bb3" xlink:to="loc_us-gaap_ProfitLoss_3c8db803-1c24-4969-9cb4-c591cbe7a397" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_b71772a9-1157-42cf-a69b-8686fec11115" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_d0db76a6-9881-4dd7-b1d4-e7e322a41bb3" xlink:to="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_b71772a9-1157-42cf-a69b-8686fec11115" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_AdjustmentDepreciationAndAmortization_693bbae9-bed0-4326-ab67-ba82830ffced" xlink:href="frt-20230630.xsd#frt_AdjustmentDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_b71772a9-1157-42cf-a69b-8686fec11115" xlink:to="loc_frt_AdjustmentDepreciationAndAmortization_693bbae9-bed0-4326-ab67-ba82830ffced" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_GainOnSaleOfRealEstate_c17ad286-2ce0-461b-9b07-9aee97daae0e" xlink:href="frt-20230630.xsd#frt_GainOnSaleOfRealEstate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_b71772a9-1157-42cf-a69b-8686fec11115" xlink:to="loc_frt_GainOnSaleOfRealEstate_c17ad286-2ce0-461b-9b07-9aee97daae0e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_b6b10907-74ad-4bd3-bcf6-b71313ac20df" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_b71772a9-1157-42cf-a69b-8686fec11115" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_b6b10907-74ad-4bd3-bcf6-b71313ac20df" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StraightLineRent_b94b033c-4d3c-424c-8b8d-0b9810939102" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StraightLineRent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_b71772a9-1157-42cf-a69b-8686fec11115" xlink:to="loc_us-gaap_StraightLineRent_b94b033c-4d3c-424c-8b8d-0b9810939102" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_3f97bce7-f82a-4263-acba-85a06bc31dc2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_b71772a9-1157-42cf-a69b-8686fec11115" xlink:to="loc_us-gaap_ShareBasedCompensation_3f97bce7-f82a-4263-acba-85a06bc31dc2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense_d4143e30-14af-4cd3-917b-b823cb2f1d47" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherNoncashIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_b71772a9-1157-42cf-a69b-8686fec11115" xlink:to="loc_us-gaap_OtherNoncashIncomeExpense_d4143e30-14af-4cd3-917b-b823cb2f1d47" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_66df626b-0e1c-4639-994a-9815f7652581" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_d0db76a6-9881-4dd7-b1d4-e7e322a41bb3" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_66df626b-0e1c-4639-994a-9815f7652581" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables_5643b52b-dd2e-4706-8de6-e9cace6fe944" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_66df626b-0e1c-4639-994a-9815f7652581" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables_5643b52b-dd2e-4706-8de6-e9cace6fe944" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_39901abc-393d-457a-b24f-7149f84b81ff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_66df626b-0e1c-4639-994a-9815f7652581" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_39901abc-393d-457a-b24f-7149f84b81ff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_b3ba6328-711f-47b8-a5b4-d34595a2b009" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_66df626b-0e1c-4639-994a-9815f7652581" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_b3ba6328-711f-47b8-a5b4-d34595a2b009" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_IncreaseDecreaseInSecurityDepositsAndOtherLiabilities_056fd0a8-cb51-46c2-855b-b042efab5293" xlink:href="frt-20230630.xsd#frt_IncreaseDecreaseInSecurityDepositsAndOtherLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_66df626b-0e1c-4639-994a-9815f7652581" xlink:to="loc_frt_IncreaseDecreaseInSecurityDepositsAndOtherLiabilities_056fd0a8-cb51-46c2-855b-b042efab5293" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5ab34a6e-ab79-410f-83e5-90dd01b33164" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_d0db76a6-9881-4dd7-b1d4-e7e322a41bb3" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5ab34a6e-ab79-410f-83e5-90dd01b33164" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_54e3a5f0-2493-4a70-9e11-05bbd36f7107" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2cc52e5b-4276-47d7-b771-fb518bc3ba4e" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_54e3a5f0-2493-4a70-9e11-05bbd36f7107" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireRealEstate_b42bf4f4-fffd-4fdd-baf1-6edc7e79a614" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquireRealEstate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_54e3a5f0-2493-4a70-9e11-05bbd36f7107" xlink:to="loc_us-gaap_PaymentsToAcquireRealEstate_b42bf4f4-fffd-4fdd-baf1-6edc7e79a614" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_CapitalExpendituresDevelopmentRedevelopment_20170431-5aab-4b22-a778-3e57188123de" xlink:href="frt-20230630.xsd#frt_CapitalExpendituresDevelopmentRedevelopment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_54e3a5f0-2493-4a70-9e11-05bbd36f7107" xlink:to="loc_frt_CapitalExpendituresDevelopmentRedevelopment_20170431-5aab-4b22-a778-3e57188123de" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_CapitalExpendituresOther_f2902474-4ff4-460f-bca9-5bef9da2f0cc" xlink:href="frt-20230630.xsd#frt_CapitalExpendituresOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_54e3a5f0-2493-4a70-9e11-05bbd36f7107" xlink:to="loc_frt_CapitalExpendituresOther_f2902474-4ff4-460f-bca9-5bef9da2f0cc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromRealEstateAndRealEstateJointVentures_50138331-d91d-43ce-9298-87fe2445fd8f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromRealEstateAndRealEstateJointVentures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_54e3a5f0-2493-4a70-9e11-05bbd36f7107" xlink:to="loc_us-gaap_ProceedsFromRealEstateAndRealEstateJointVentures_50138331-d91d-43ce-9298-87fe2445fd8f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireInterestInSubsidiariesAndAffiliates_22c175f0-70ae-4a5a-9c83-7439d6d58b76" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquireInterestInSubsidiariesAndAffiliates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_54e3a5f0-2493-4a70-9e11-05bbd36f7107" xlink:to="loc_us-gaap_PaymentsToAcquireInterestInSubsidiariesAndAffiliates_22c175f0-70ae-4a5a-9c83-7439d6d58b76" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDistributionsReceivedFromRealEstatePartnerships_920e2956-32f0-43b5-a867-55f3565eb01a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromDistributionsReceivedFromRealEstatePartnerships"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_54e3a5f0-2493-4a70-9e11-05bbd36f7107" xlink:to="loc_us-gaap_ProceedsFromDistributionsReceivedFromRealEstatePartnerships_920e2956-32f0-43b5-a867-55f3565eb01a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInLeaseAcquisitionCosts_1a8a728b-a63b-4248-bf1d-c9dfbea67188" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInLeaseAcquisitionCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_54e3a5f0-2493-4a70-9e11-05bbd36f7107" xlink:to="loc_us-gaap_IncreaseDecreaseInLeaseAcquisitionCosts_1a8a728b-a63b-4248-bf1d-c9dfbea67188" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_IssuanceAndRepaymentsOfMortgageAndOtherNotesReceivableNet_1b425e99-368e-40b0-b8cb-3d9bfb693fbb" xlink:href="frt-20230630.xsd#frt_IssuanceAndRepaymentsOfMortgageAndOtherNotesReceivableNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_54e3a5f0-2493-4a70-9e11-05bbd36f7107" xlink:to="loc_frt_IssuanceAndRepaymentsOfMortgageAndOtherNotesReceivableNet_1b425e99-368e-40b0-b8cb-3d9bfb693fbb" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_d90e3429-f7dc-4697-a969-af6f3516dcd3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_54e3a5f0-2493-4a70-9e11-05bbd36f7107" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_d90e3429-f7dc-4697-a969-af6f3516dcd3" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_081d48f3-c544-4c0b-a52c-004ce1c00f9b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2cc52e5b-4276-47d7-b771-fb518bc3ba4e" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_081d48f3-c544-4c0b-a52c-004ce1c00f9b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromRepaymentsOfLinesOfCredit_db519181-43a3-4f24-89bb-c2167bc2e356" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromRepaymentsOfLinesOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_081d48f3-c544-4c0b-a52c-004ce1c00f9b" xlink:to="loc_us-gaap_ProceedsFromRepaymentsOfLinesOfCredit_db519181-43a3-4f24-89bb-c2167bc2e356" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt_5a156358-31a3-4085-ae37-fd4244f85883" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_081d48f3-c544-4c0b-a52c-004ce1c00f9b" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt_5a156358-31a3-4085-ae37-fd4244f85883" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfSeniorDebt_1d12c903-4547-48cc-941f-978da082dfb7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RepaymentsOfSeniorDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_081d48f3-c544-4c0b-a52c-004ce1c00f9b" xlink:to="loc_us-gaap_RepaymentsOfSeniorDebt_1d12c903-4547-48cc-941f-978da082dfb7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_RepaymentOfMortgagesFinanceLeasesAndNotesPayable_87f20138-6778-4dcb-a705-7e110e627e68" xlink:href="frt-20230630.xsd#frt_RepaymentOfMortgagesFinanceLeasesAndNotesPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_081d48f3-c544-4c0b-a52c-004ce1c00f9b" xlink:to="loc_frt_RepaymentOfMortgagesFinanceLeasesAndNotesPayable_87f20138-6778-4dcb-a705-7e110e627e68" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_7e90af21-fb91-4170-aa0e-306094e645d3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_081d48f3-c544-4c0b-a52c-004ce1c00f9b" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_7e90af21-fb91-4170-aa0e-306094e645d3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_DividendsPaidToCommonAndPreferredShareholders_53e25eae-762c-4ff0-bfe1-db5978e36ea9" xlink:href="frt-20230630.xsd#frt_DividendsPaidToCommonAndPreferredShareholders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_081d48f3-c544-4c0b-a52c-004ce1c00f9b" xlink:to="loc_frt_DividendsPaidToCommonAndPreferredShareholders_53e25eae-762c-4ff0-bfe1-db5978e36ea9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_1a9439b5-bb09-46bd-8f57-18d0c34154c9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_081d48f3-c544-4c0b-a52c-004ce1c00f9b" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_1a9439b5-bb09-46bd-8f57-18d0c34154c9" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromMinorityShareholders_20157ae5-c17b-4f17-b367-792ba8db8a9e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromMinorityShareholders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_081d48f3-c544-4c0b-a52c-004ce1c00f9b" xlink:to="loc_us-gaap_ProceedsFromMinorityShareholders_20157ae5-c17b-4f17-b367-792ba8db8a9e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_Paymentsofdividendsandredemptionsminorityinterest_5ded1f30-c35e-408a-9ac1-ffac511966a7" xlink:href="frt-20230630.xsd#frt_Paymentsofdividendsandredemptionsminorityinterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_081d48f3-c544-4c0b-a52c-004ce1c00f9b" xlink:to="loc_frt_Paymentsofdividendsandredemptionsminorityinterest_5ded1f30-c35e-408a-9ac1-ffac511966a7" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_614ca7ea-5e26-4c2c-ae42-8bfdb496ab32" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_081d48f3-c544-4c0b-a52c-004ce1c00f9b" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_614ca7ea-5e26-4c2c-ae42-8bfdb496ab32" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_cba01ce4-86d8-445e-aa53-1659dbe42673" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2cc52e5b-4276-47d7-b771-fb518bc3ba4e" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_cba01ce4-86d8-445e-aa53-1659dbe42673" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_db21a81a-a316-409f-8194-7d84f893c2e8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2cc52e5b-4276-47d7-b771-fb518bc3ba4e" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_db21a81a-a316-409f-8194-7d84f893c2e8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_b37f5a38-54ff-445b-ba4e-d867f9432e25" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_0a02f5a0-0e45-4fcc-a205-b520b3ba2963" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2cc52e5b-4276-47d7-b771-fb518bc3ba4e" xlink:to="loc_us-gaap_StatementTable_0a02f5a0-0e45-4fcc-a205-b520b3ba2963" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_9c5a1fd8-8ec1-4358-9fdc-73193b4717f8" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_0a02f5a0-0e45-4fcc-a205-b520b3ba2963" xlink:to="loc_srt_ConsolidatedEntitiesAxis_9c5a1fd8-8ec1-4358-9fdc-73193b4717f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_9c5a1fd8-8ec1-4358-9fdc-73193b4717f8_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_9c5a1fd8-8ec1-4358-9fdc-73193b4717f8" xlink:to="loc_srt_ConsolidatedEntitiesDomain_9c5a1fd8-8ec1-4358-9fdc-73193b4717f8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_2ea4e3cf-eb46-409f-bef0-858b529c5413" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_9c5a1fd8-8ec1-4358-9fdc-73193b4717f8" xlink:to="loc_srt_ConsolidatedEntitiesDomain_2ea4e3cf-eb46-409f-bef0-858b529c5413" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_PartnershipInterestMember_31f4e799-320d-4193-a3a2-d518b7debf15" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_PartnershipInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_2ea4e3cf-eb46-409f-bef0-858b529c5413" xlink:to="loc_srt_PartnershipInterestMember_31f4e799-320d-4193-a3a2-d518b7debf15" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/ConsolidatedStatementsofCapital" xlink:type="simple" xlink:href="frt-20230630.xsd#ConsolidatedStatementsofCapital"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ConsolidatedStatementsofCapital" xlink:type="extended" id="ifdfec918787f40c9853311facfb7cb58_ConsolidatedStatementsofCapital">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_9beda3dd-40bb-4c42-8e7c-0310864553b3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInPartnersCapitalRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_9beda3dd-40bb-4c42-8e7c-0310864553b3" xlink:to="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest_10a1239e-ac83-4935-a315-0e3c5aabdcbc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest_10a1239e-ac83-4935-a315-0e3c5aabdcbc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_5310617d-75c5-48ca-bead-d1cbc25d9a17" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_5310617d-75c5-48ca-bead-d1cbc25d9a17" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_OtherComprehensiveIncomeLossNetOfPortionAttributableToNoncontrollingInterest_92c78609-6675-4731-a027-ea2e792fd350" xlink:href="frt-20230630.xsd#frt_OtherComprehensiveIncomeLossNetOfPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_frt_OtherComprehensiveIncomeLossNetOfPortionAttributableToNoncontrollingInterest_92c78609-6675-4731-a027-ea2e792fd350" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_DistributionsDeclaredToCommonUnitHolders_2d8f2b21-9020-46ae-b391-a4ec5ddf8434" xlink:href="frt-20230630.xsd#frt_DistributionsDeclaredToCommonUnitHolders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_frt_DistributionsDeclaredToCommonUnitHolders_2d8f2b21-9020-46ae-b391-a4ec5ddf8434" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_DistributionsDeclaredToPreferredUnitHolders_f6f0e846-3f3d-4a92-84f7-a09a62d25cc0" xlink:href="frt-20230630.xsd#frt_DistributionsDeclaredToPreferredUnitHolders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_frt_DistributionsDeclaredToPreferredUnitHolders_f6f0e846-3f3d-4a92-84f7-a09a62d25cc0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_DistributionsDeclaredToNoncontrollingInterestsInConsolidatedPartnershipsExcludingAmountsAttributableToRedeemableNoncontrollingInterests_ff17e4b2-4982-406f-84dd-d5b186be3792" xlink:href="frt-20230630.xsd#frt_DistributionsDeclaredToNoncontrollingInterestsInConsolidatedPartnershipsExcludingAmountsAttributableToRedeemableNoncontrollingInterests"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_frt_DistributionsDeclaredToNoncontrollingInterestsInConsolidatedPartnershipsExcludingAmountsAttributableToRedeemableNoncontrollingInterests_ff17e4b2-4982-406f-84dd-d5b186be3792" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalAccountContributions_4b6c7057-d632-4109-af55-aa9f7e922f8a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalAccountContributions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_us-gaap_PartnersCapitalAccountContributions_4b6c7057-d632-4109-af55-aa9f7e922f8a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_CommonUnitsIssuedUnderDividendReinvestmentPlan_1e13137d-983c-4dbe-9f8d-1d704bc19f60" xlink:href="frt-20230630.xsd#frt_CommonUnitsIssuedUnderDividendReinvestmentPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_frt_CommonUnitsIssuedUnderDividendReinvestmentPlan_1e13137d-983c-4dbe-9f8d-1d704bc19f60" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalAccountUnitBasedCompensation_914bad8d-a680-49e9-952b-745edacc541c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalAccountUnitBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_us-gaap_PartnersCapitalAccountUnitBasedCompensation_914bad8d-a680-49e9-952b-745edacc541c" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_PartnersCapitalAccountEmployeeTaxWithholdings_3be8c516-5f8d-417b-96ad-39a1666fcb8c" xlink:href="frt-20230630.xsd#frt_PartnersCapitalAccountEmployeeTaxWithholdings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_frt_PartnersCapitalAccountEmployeeTaxWithholdings_3be8c516-5f8d-417b-96ad-39a1666fcb8c" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ConversionOfPreferredUnitsValue_3bc5c959-4b78-4546-bebe-88825947e734" xlink:href="frt-20230630.xsd#frt_ConversionOfPreferredUnitsValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_frt_ConversionOfPreferredUnitsValue_3bc5c959-4b78-4546-bebe-88825947e734" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ConversionOfPreferredUnits_cf5796b2-4aa1-4a78-a3f1-263bb567e2de" xlink:href="frt-20230630.xsd#frt_ConversionOfPreferredUnits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_frt_ConversionOfPreferredUnits_cf5796b2-4aa1-4a78-a3f1-263bb567e2de" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_Contributionsfromnoncontrollinginterests_538a294a-5daa-4298-a45d-f8c561728b64" xlink:href="frt-20230630.xsd#frt_Contributionsfromnoncontrollinginterests"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_frt_Contributionsfromnoncontrollinginterests_538a294a-5daa-4298-a45d-f8c561728b64" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalAccountExchangesAndConversions_ee2939ed-b6bb-4971-bee5-1d177d2dba28" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalAccountExchangesAndConversions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_us-gaap_PartnersCapitalAccountExchangesAndConversions_ee2939ed-b6bb-4971-bee5-1d177d2dba28" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalOther_fec403a6-4364-4eff-973e-8c07a10b552a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_89a745bf-8312-40a6-825a-fffa5c89c60e" xlink:to="loc_us-gaap_PartnersCapitalOther_fec403a6-4364-4eff-973e-8c07a10b552a" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest_b9071669-e6c2-4f84-b2a0-ba8b2bbbb783" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_75332fb7-37aa-4149-ad3a-e143c1cfc303" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_9beda3dd-40bb-4c42-8e7c-0310864553b3" xlink:to="loc_us-gaap_StatementTable_75332fb7-37aa-4149-ad3a-e143c1cfc303" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_2107135e-4299-4274-8b16-199576c2e7a9" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_75332fb7-37aa-4149-ad3a-e143c1cfc303" xlink:to="loc_srt_ConsolidatedEntitiesAxis_2107135e-4299-4274-8b16-199576c2e7a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_2107135e-4299-4274-8b16-199576c2e7a9_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_2107135e-4299-4274-8b16-199576c2e7a9" xlink:to="loc_srt_ConsolidatedEntitiesDomain_2107135e-4299-4274-8b16-199576c2e7a9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_8957dda3-54aa-48cb-a47c-f8179bef0f5c" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_2107135e-4299-4274-8b16-199576c2e7a9" xlink:to="loc_srt_ConsolidatedEntitiesDomain_8957dda3-54aa-48cb-a47c-f8179bef0f5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_PartnershipInterestMember_94f6bb29-b086-4f3a-86f0-7f218edadd09" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_PartnershipInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_8957dda3-54aa-48cb-a47c-f8179bef0f5c" xlink:to="loc_srt_PartnershipInterestMember_94f6bb29-b086-4f3a-86f0-7f218edadd09" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ConvertibleUnitTypeAxis_db227e73-040d-4e38-8ad2-eec329de7c0d" xlink:href="frt-20230630.xsd#frt_ConvertibleUnitTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_75332fb7-37aa-4149-ad3a-e143c1cfc303" xlink:to="loc_frt_ConvertibleUnitTypeAxis_db227e73-040d-4e38-8ad2-eec329de7c0d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ConvertibleUnitTypeDomain_db227e73-040d-4e38-8ad2-eec329de7c0d_default" xlink:href="frt-20230630.xsd#frt_ConvertibleUnitTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_frt_ConvertibleUnitTypeAxis_db227e73-040d-4e38-8ad2-eec329de7c0d" xlink:to="loc_frt_ConvertibleUnitTypeDomain_db227e73-040d-4e38-8ad2-eec329de7c0d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ConvertibleUnitTypeDomain_147a5862-21c4-4a7a-818c-ec70c8ccb342" xlink:href="frt-20230630.xsd#frt_ConvertibleUnitTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_frt_ConvertibleUnitTypeAxis_db227e73-040d-4e38-8ad2-eec329de7c0d" xlink:to="loc_frt_ConvertibleUnitTypeDomain_147a5862-21c4-4a7a-818c-ec70c8ccb342" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_DownREITOPUnitsMember_bcd32e6d-f330-4e74-965d-f75be722afc5" xlink:href="frt-20230630.xsd#frt_DownREITOPUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_ConvertibleUnitTypeDomain_147a5862-21c4-4a7a-818c-ec70c8ccb342" xlink:to="loc_frt_DownREITOPUnitsMember_bcd32e6d-f330-4e74-965d-f75be722afc5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_7058eb53-3d33-40e7-b7f6-db45224874f6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_75332fb7-37aa-4149-ad3a-e143c1cfc303" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_7058eb53-3d33-40e7-b7f6-db45224874f6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_7058eb53-3d33-40e7-b7f6-db45224874f6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_7058eb53-3d33-40e7-b7f6-db45224874f6" xlink:to="loc_us-gaap_EquityComponentDomain_7058eb53-3d33-40e7-b7f6-db45224874f6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_a36365d9-410d-4b9d-9ba8-ae44cf6d0e47" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_7058eb53-3d33-40e7-b7f6-db45224874f6" xlink:to="loc_us-gaap_EquityComponentDomain_a36365d9-410d-4b9d-9ba8-ae44cf6d0e47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_PreferredUnitsMember_86e4dccc-195b-4991-b2a4-31ef0a0b0728" xlink:href="frt-20230630.xsd#frt_PreferredUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a36365d9-410d-4b9d-9ba8-ae44cf6d0e47" xlink:to="loc_frt_PreferredUnitsMember_86e4dccc-195b-4991-b2a4-31ef0a0b0728" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_CommonUnitsMember_a8fc1772-9c79-4434-89de-1a7e888bf8d5" xlink:href="frt-20230630.xsd#frt_CommonUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a36365d9-410d-4b9d-9ba8-ae44cf6d0e47" xlink:to="loc_frt_CommonUnitsMember_a8fc1772-9c79-4434-89de-1a7e888bf8d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8364bb3a-9d59-4a7e-86b3-b0ec1e33ba01" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a36365d9-410d-4b9d-9ba8-ae44cf6d0e47" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8364bb3a-9d59-4a7e-86b3-b0ec1e33ba01" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParentMember_cbc98505-975d-4d4c-92ac-17457709f94e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a36365d9-410d-4b9d-9ba8-ae44cf6d0e47" xlink:to="loc_us-gaap_ParentMember_cbc98505-975d-4d4c-92ac-17457709f94e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_NoncontrollingInterestsInConsolidatedPartnershipsMember_89ceec69-6953-4226-b76d-da3803f13e81" xlink:href="frt-20230630.xsd#frt_NoncontrollingInterestsInConsolidatedPartnershipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a36365d9-410d-4b9d-9ba8-ae44cf6d0e47" xlink:to="loc_frt_NoncontrollingInterestsInConsolidatedPartnershipsMember_89ceec69-6953-4226-b76d-da3803f13e81" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/ConsolidatedStatementsofCapitalParenthetical" xlink:type="simple" xlink:href="frt-20230630.xsd#ConsolidatedStatementsofCapitalParenthetical"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ConsolidatedStatementsofCapitalParenthetical" xlink:type="extended" id="ibabe2fc907ec4edbbda412f9d3885ea6_ConsolidatedStatementsofCapitalParenthetical">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_358b85ad-0f9b-42a2-9efc-cb0e221efddd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest_9d71a61e-508c-4e05-af67-4d7cb23b58b6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_358b85ad-0f9b-42a2-9efc-cb0e221efddd" xlink:to="loc_us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest_9d71a61e-508c-4e05-af67-4d7cb23b58b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_OtherComprehensiveIncomeLossAttributableToRedeemableNoncontrollingInterest_842dec13-5ce6-4155-9a2c-8a167f37861d" xlink:href="frt-20230630.xsd#frt_OtherComprehensiveIncomeLossAttributableToRedeemableNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_358b85ad-0f9b-42a2-9efc-cb0e221efddd" xlink:to="loc_frt_OtherComprehensiveIncomeLossAttributableToRedeemableNoncontrollingInterest_842dec13-5ce6-4155-9a2c-8a167f37861d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_RedeemableNoncontrollingInterestDecreaseFromDistributionsToRedeemableNoncontrollingInterestHolders_a3872023-2ccb-4800-b5a9-36d6596dda52" xlink:href="frt-20230630.xsd#frt_RedeemableNoncontrollingInterestDecreaseFromDistributionsToRedeemableNoncontrollingInterestHolders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_358b85ad-0f9b-42a2-9efc-cb0e221efddd" xlink:to="loc_frt_RedeemableNoncontrollingInterestDecreaseFromDistributionsToRedeemableNoncontrollingInterestHolders_a3872023-2ccb-4800-b5a9-36d6596dda52" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_5d2e81cf-6dcb-4482-8191-09951d57e0ce" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_358b85ad-0f9b-42a2-9efc-cb0e221efddd" xlink:to="loc_us-gaap_StatementTable_5d2e81cf-6dcb-4482-8191-09951d57e0ce" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_2f7a68f6-6cd4-4048-96d6-da220c9eb929" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_5d2e81cf-6dcb-4482-8191-09951d57e0ce" xlink:to="loc_srt_ConsolidatedEntitiesAxis_2f7a68f6-6cd4-4048-96d6-da220c9eb929" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_2f7a68f6-6cd4-4048-96d6-da220c9eb929_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_2f7a68f6-6cd4-4048-96d6-da220c9eb929" xlink:to="loc_srt_ConsolidatedEntitiesDomain_2f7a68f6-6cd4-4048-96d6-da220c9eb929_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_655a1b07-0c33-434a-8789-eeea1b6a5810" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_2f7a68f6-6cd4-4048-96d6-da220c9eb929" xlink:to="loc_srt_ConsolidatedEntitiesDomain_655a1b07-0c33-434a-8789-eeea1b6a5810" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_PartnershipInterestMember_c8273c93-0ba8-4811-887d-ab59faaefb36" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_PartnershipInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_655a1b07-0c33-434a-8789-eeea1b6a5810" xlink:to="loc_srt_PartnershipInterestMember_c8273c93-0ba8-4811-887d-ab59faaefb36" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_7e978370-8913-443f-9af3-950e737a6748" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_5d2e81cf-6dcb-4482-8191-09951d57e0ce" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_7e978370-8913-443f-9af3-950e737a6748" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_7e978370-8913-443f-9af3-950e737a6748_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_7e978370-8913-443f-9af3-950e737a6748" xlink:to="loc_us-gaap_EquityComponentDomain_7e978370-8913-443f-9af3-950e737a6748_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_128bde05-4f01-4961-a766-b46ddb4a6a31" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_7e978370-8913-443f-9af3-950e737a6748" xlink:to="loc_us-gaap_EquityComponentDomain_128bde05-4f01-4961-a766-b46ddb4a6a31" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_PreferredUnitsMember_0cb0789e-d790-4f41-9bc7-f6e6cce85470" xlink:href="frt-20230630.xsd#frt_PreferredUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_128bde05-4f01-4961-a766-b46ddb4a6a31" xlink:to="loc_frt_PreferredUnitsMember_0cb0789e-d790-4f41-9bc7-f6e6cce85470" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_CommonUnitsMember_b5068856-1757-4cb0-985d-342d2d2b96d9" xlink:href="frt-20230630.xsd#frt_CommonUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_128bde05-4f01-4961-a766-b46ddb4a6a31" xlink:to="loc_frt_CommonUnitsMember_b5068856-1757-4cb0-985d-342d2d2b96d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_92cc1026-884a-4f19-8ac2-255d13b910b4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_128bde05-4f01-4961-a766-b46ddb4a6a31" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_92cc1026-884a-4f19-8ac2-255d13b910b4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParentMember_f1b72c8b-47c1-4294-b82f-a1005a0adc59" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_128bde05-4f01-4961-a766-b46ddb4a6a31" xlink:to="loc_us-gaap_ParentMember_f1b72c8b-47c1-4294-b82f-a1005a0adc59" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_NoncontrollingInterestsInConsolidatedPartnershipsMember_999d69fa-bc07-4323-a995-c52a861513d9" xlink:href="frt-20230630.xsd#frt_NoncontrollingInterestsInConsolidatedPartnershipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_128bde05-4f01-4961-a766-b46ddb4a6a31" xlink:to="loc_frt_NoncontrollingInterestsInConsolidatedPartnershipsMember_999d69fa-bc07-4323-a995-c52a861513d9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ConvertibleUnitTypeAxis_f047f3d8-50f4-462b-85b8-a7c6b666900e" xlink:href="frt-20230630.xsd#frt_ConvertibleUnitTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_5d2e81cf-6dcb-4482-8191-09951d57e0ce" xlink:to="loc_frt_ConvertibleUnitTypeAxis_f047f3d8-50f4-462b-85b8-a7c6b666900e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ConvertibleUnitTypeDomain_f047f3d8-50f4-462b-85b8-a7c6b666900e_default" xlink:href="frt-20230630.xsd#frt_ConvertibleUnitTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_frt_ConvertibleUnitTypeAxis_f047f3d8-50f4-462b-85b8-a7c6b666900e" xlink:to="loc_frt_ConvertibleUnitTypeDomain_f047f3d8-50f4-462b-85b8-a7c6b666900e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ConvertibleUnitTypeDomain_8a215080-2abc-4c83-a9c1-b9afa293f73a" xlink:href="frt-20230630.xsd#frt_ConvertibleUnitTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_frt_ConvertibleUnitTypeAxis_f047f3d8-50f4-462b-85b8-a7c6b666900e" xlink:to="loc_frt_ConvertibleUnitTypeDomain_8a215080-2abc-4c83-a9c1-b9afa293f73a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_DownREITOPUnitsMember_6fc2caf8-a1ff-4e92-ab2a-6e0f7c6c55f3" xlink:href="frt-20230630.xsd#frt_DownREITOPUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_ConvertibleUnitTypeDomain_8a215080-2abc-4c83-a9c1-b9afa293f73a" xlink:to="loc_frt_DownREITOPUnitsMember_6fc2caf8-a1ff-4e92-ab2a-6e0f7c6c55f3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_A5417Series1CumulativeConvertiblePreferredMember_cbc13cd3-37e3-4cee-a4af-3f55c68bc818" xlink:href="frt-20230630.xsd#frt_A5417Series1CumulativeConvertiblePreferredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_ConvertibleUnitTypeDomain_8a215080-2abc-4c83-a9c1-b9afa293f73a" xlink:to="loc_frt_A5417Series1CumulativeConvertiblePreferredMember_cbc13cd3-37e3-4cee-a4af-3f55c68bc818" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_ac19a388-2425-43da-b1be-1294cd6b1e68" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_5d2e81cf-6dcb-4482-8191-09951d57e0ce" xlink:to="loc_us-gaap_StatementClassOfStockAxis_ac19a388-2425-43da-b1be-1294cd6b1e68" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_ac19a388-2425-43da-b1be-1294cd6b1e68_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_ac19a388-2425-43da-b1be-1294cd6b1e68" xlink:to="loc_us-gaap_ClassOfStockDomain_ac19a388-2425-43da-b1be-1294cd6b1e68_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_71f34341-ade9-480e-94be-5f12156eb153" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_ac19a388-2425-43da-b1be-1294cd6b1e68" xlink:to="loc_us-gaap_ClassOfStockDomain_71f34341-ade9-480e-94be-5f12156eb153" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/BusinessAndOrganizationDetails" xlink:type="simple" xlink:href="frt-20230630.xsd#BusinessAndOrganizationDetails"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/BusinessAndOrganizationDetails" xlink:type="extended" id="ib5dbff3a3e4b4439933534fef5445fb7_BusinessAndOrganizationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipLineItems_bc215c43-449c-41be-ae4a-7f458925da81" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterest_b2b7f2c0-b9e7-4249-89cf-7f607dc319ab" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipLineItems_bc215c43-449c-41be-ae4a-7f458925da81" xlink:to="loc_us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterest_b2b7f2c0-b9e7-4249-89cf-7f607dc319ab" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfRealEstateProperties_6ec032df-4957-4664-b17e-a556abc067b9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NumberOfRealEstateProperties"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipLineItems_bc215c43-449c-41be-ae4a-7f458925da81" xlink:to="loc_us-gaap_NumberOfRealEstateProperties_6ec032df-4957-4664-b17e-a556abc067b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_MinimumPercentageOfTaxableIncomeDistributedToShareholders_34876c52-949d-4f40-b451-1d7672a4f6e8" xlink:href="frt-20230630.xsd#frt_MinimumPercentageOfTaxableIncomeDistributedToShareholders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipLineItems_bc215c43-449c-41be-ae4a-7f458925da81" xlink:to="loc_frt_MinimumPercentageOfTaxableIncomeDistributedToShareholders_34876c52-949d-4f40-b451-1d7672a4f6e8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipTable_ec2ede84-a39c-46e6-8506-462ab60ebdf7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfSubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipLineItems_bc215c43-449c-41be-ae4a-7f458925da81" xlink:to="loc_us-gaap_ScheduleOfSubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipTable_ec2ede84-a39c-46e6-8506-462ab60ebdf7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_3c2a37a8-5f90-4f27-8fc5-c8ce7d6db2d6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipTable_ec2ede84-a39c-46e6-8506-462ab60ebdf7" xlink:to="loc_srt_OwnershipAxis_3c2a37a8-5f90-4f27-8fc5-c8ce7d6db2d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_3c2a37a8-5f90-4f27-8fc5-c8ce7d6db2d6_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_3c2a37a8-5f90-4f27-8fc5-c8ce7d6db2d6" xlink:to="loc_srt_OwnershipDomain_3c2a37a8-5f90-4f27-8fc5-c8ce7d6db2d6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_e3118d3e-d5d8-457f-a948-254184b1b028" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_3c2a37a8-5f90-4f27-8fc5-c8ce7d6db2d6" xlink:to="loc_srt_OwnershipDomain_e3118d3e-d5d8-457f-a948-254184b1b028" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_FederalRealtyGPLLCMember_3098c4f6-4d9e-4464-9e6b-b27d9c97eb94" xlink:href="frt-20230630.xsd#frt_FederalRealtyGPLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_e3118d3e-d5d8-457f-a948-254184b1b028" xlink:to="loc_frt_FederalRealtyGPLLCMember_3098c4f6-4d9e-4464-9e6b-b27d9c97eb94" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/SummaryOfSignificantAccountingPoliciesRecentlyIssuedAccountingPronouncementsDetails" xlink:type="simple" xlink:href="frt-20230630.xsd#SummaryOfSignificantAccountingPoliciesRecentlyIssuedAccountingPronouncementsDetails"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/SummaryOfSignificantAccountingPoliciesRecentlyIssuedAccountingPronouncementsDetails" xlink:type="extended" id="i25338a2bc30b4de6856d710d5b8bff74_SummaryOfSignificantAccountingPoliciesRecentlyIssuedAccountingPronouncementsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_ec6bf0e7-2256-4353-a762-4d3ec169680a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_e61dd4e9-fcac-4f6f-a2b7-e42f4456850b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_ec6bf0e7-2256-4353-a762-4d3ec169680a" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_e61dd4e9-fcac-4f6f-a2b7-e42f4456850b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_039001f8-8337-4a47-9143-05750012560a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_ec6bf0e7-2256-4353-a762-4d3ec169680a" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_039001f8-8337-4a47-9143-05750012560a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_53b6f00b-0f04-4f02-8a8c-2820e36e9595" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_039001f8-8337-4a47-9143-05750012560a" xlink:to="loc_us-gaap_DebtInstrumentAxis_53b6f00b-0f04-4f02-8a8c-2820e36e9595" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_53b6f00b-0f04-4f02-8a8c-2820e36e9595_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_53b6f00b-0f04-4f02-8a8c-2820e36e9595" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_53b6f00b-0f04-4f02-8a8c-2820e36e9595_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_cc02100d-0fd0-4593-8ba7-26ee7367f986" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_53b6f00b-0f04-4f02-8a8c-2820e36e9595" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_cc02100d-0fd0-4593-8ba7-26ee7367f986" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_HobokenMember_aaf55b00-b4ae-4880-bc07-7c6e7ca9764a" xlink:href="frt-20230630.xsd#frt_HobokenMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cc02100d-0fd0-4593-8ba7-26ee7367f986" xlink:to="loc_frt_HobokenMember_aaf55b00-b4ae-4880-bc07-7c6e7ca9764a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_87d2f94e-07c9-4d37-a503-3d5b0cee08ca" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_039001f8-8337-4a47-9143-05750012560a" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_87d2f94e-07c9-4d37-a503-3d5b0cee08ca" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_87d2f94e-07c9-4d37-a503-3d5b0cee08ca_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_87d2f94e-07c9-4d37-a503-3d5b0cee08ca" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_87d2f94e-07c9-4d37-a503-3d5b0cee08ca_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_cf1992e5-97c0-4cfc-bc96-a869ef2bb981" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_87d2f94e-07c9-4d37-a503-3d5b0cee08ca" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_cf1992e5-97c0-4cfc-bc96-a869ef2bb981" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_a2138ed0-0c0c-4c49-8f21-8938d512ad54" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_cf1992e5-97c0-4cfc-bc96-a869ef2bb981" xlink:to="loc_us-gaap_SecuredDebtMember_a2138ed0-0c0c-4c49-8f21-8938d512ad54" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/RealEstateSignificantAcquisitionandDispositionDetails" xlink:type="simple" xlink:href="frt-20230630.xsd#RealEstateSignificantAcquisitionandDispositionDetails"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/RealEstateSignificantAcquisitionandDispositionDetails" xlink:type="extended" id="icbc15a2f7ce349a7bdc0d885f85a2b7a_RealEstateSignificantAcquisitionandDispositionDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_8db07893-9f9a-4b70-aed3-11e44acb8769" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AreaOfRealEstateProperty_340398f7-c04f-40ef-beec-d530742ae6c0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AreaOfRealEstateProperty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8db07893-9f9a-4b70-aed3-11e44acb8769" xlink:to="loc_us-gaap_AreaOfRealEstateProperty_340398f7-c04f-40ef-beec-d530742ae6c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_PurchasePriceOfFeeInterestInRealEstate_5b64f0c3-a295-43ee-86e7-cda96aa974fc" xlink:href="frt-20230630.xsd#frt_PurchasePriceOfFeeInterestInRealEstate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8db07893-9f9a-4b70-aed3-11e44acb8769" xlink:to="loc_frt_PurchasePriceOfFeeInterestInRealEstate_5b64f0c3-a295-43ee-86e7-cda96aa974fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_DecreaseOfOperatingLeaseRightOfUseAssetsNet_189fcd69-3f6b-4b42-9660-57ebf43a35e3" xlink:href="frt-20230630.xsd#frt_DecreaseOfOperatingLeaseRightOfUseAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8db07893-9f9a-4b70-aed3-11e44acb8769" xlink:to="loc_frt_DecreaseOfOperatingLeaseRightOfUseAssetsNet_189fcd69-3f6b-4b42-9660-57ebf43a35e3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_AcquiredLeaseCosts_c1552353-3e43-441f-9788-e951f7a42201" xlink:href="frt-20230630.xsd#frt_AcquiredLeaseCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8db07893-9f9a-4b70-aed3-11e44acb8769" xlink:to="loc_frt_AcquiredLeaseCosts_c1552353-3e43-441f-9788-e951f7a42201" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_162cba74-7666-4265-ac00-8f08b53666d0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinitelivedIntangibleAssetsAcquired1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8db07893-9f9a-4b70-aed3-11e44acb8769" xlink:to="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_162cba74-7666-4265-ac00-8f08b53666d0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_OwnershipInterestOfPartnerInOurJointVenture_0e8af4f7-23d3-47f6-8e0e-2974f4a4ac0f" xlink:href="frt-20230630.xsd#frt_OwnershipInterestOfPartnerInOurJointVenture"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8db07893-9f9a-4b70-aed3-11e44acb8769" xlink:to="loc_frt_OwnershipInterestOfPartnerInOurJointVenture_0e8af4f7-23d3-47f6-8e0e-2974f4a4ac0f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_OwnershipInterestSubsequentToAcquisition_eac2ea33-9196-46c7-93cd-514876abf9f8" xlink:href="frt-20230630.xsd#frt_OwnershipInterestSubsequentToAcquisition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8db07893-9f9a-4b70-aed3-11e44acb8769" xlink:to="loc_frt_OwnershipInterestSubsequentToAcquisition_eac2ea33-9196-46c7-93cd-514876abf9f8" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BelowMarketLeaseAcquired_bf258742-ae1a-4f66-9eba-8a993346c9d7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BelowMarketLeaseAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8db07893-9f9a-4b70-aed3-11e44acb8769" xlink:to="loc_us-gaap_BelowMarketLeaseAcquired_bf258742-ae1a-4f66-9eba-8a993346c9d7" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_Salespriceofrealestate_d0740fa2-e6ae-4822-9801-83438df8f5ef" xlink:href="frt-20230630.xsd#frt_Salespriceofrealestate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8db07893-9f9a-4b70-aed3-11e44acb8769" xlink:to="loc_frt_Salespriceofrealestate_d0740fa2-e6ae-4822-9801-83438df8f5ef" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_GainOnSaleOfRealEstate_c9ee69c7-e0d8-42ea-94a6-fca40bb4cc51" xlink:href="frt-20230630.xsd#frt_GainOnSaleOfRealEstate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8db07893-9f9a-4b70-aed3-11e44acb8769" xlink:to="loc_frt_GainOnSaleOfRealEstate_c9ee69c7-e0d8-42ea-94a6-fca40bb4cc51" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_04af35df-8b20-4762-9c62-cd2ead5b7bf9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8db07893-9f9a-4b70-aed3-11e44acb8769" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_04af35df-8b20-4762-9c62-cd2ead5b7bf9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_46172274-0066-4caa-bdd3-39ab34cc2bee" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_04af35df-8b20-4762-9c62-cd2ead5b7bf9" xlink:to="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_46172274-0066-4caa-bdd3-39ab34cc2bee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_46172274-0066-4caa-bdd3-39ab34cc2bee_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_46172274-0066-4caa-bdd3-39ab34cc2bee" xlink:to="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_46172274-0066-4caa-bdd3-39ab34cc2bee_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_f8982eb4-470f-4a47-8cd6-1852fd3facb7" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_46172274-0066-4caa-bdd3-39ab34cc2bee" xlink:to="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_f8982eb4-470f-4a47-8cd6-1852fd3facb7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_APortionOfHuntingtonSquareShoppingCenterMember_b8422dcb-c968-428e-b92d-6b732f765d31" xlink:href="frt-20230630.xsd#frt_APortionOfHuntingtonSquareShoppingCenterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_f8982eb4-470f-4a47-8cd6-1852fd3facb7" xlink:to="loc_frt_APortionOfHuntingtonSquareShoppingCenterMember_b8422dcb-c968-428e-b92d-6b732f765d31" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_HuntingtonSquareShoppingCenterMember_8fd02a4d-db83-46a9-8e7c-2b7d237aecac" xlink:href="frt-20230630.xsd#frt_HuntingtonSquareShoppingCenterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_f8982eb4-470f-4a47-8cd6-1852fd3facb7" xlink:to="loc_frt_HuntingtonSquareShoppingCenterMember_8fd02a4d-db83-46a9-8e7c-2b7d237aecac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_EscondidoPromenadeMember_9d775975-b476-495f-b1e6-3a040b5309bc" xlink:href="frt-20230630.xsd#frt_EscondidoPromenadeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_f8982eb4-470f-4a47-8cd6-1852fd3facb7" xlink:to="loc_frt_EscondidoPromenadeMember_9d775975-b476-495f-b1e6-3a040b5309bc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_OneProperty2023Member_b65a8d98-3045-47fd-b692-ee09e6d940e1" xlink:href="frt-20230630.xsd#frt_OneProperty2023Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_f8982eb4-470f-4a47-8cd6-1852fd3facb7" xlink:to="loc_frt_OneProperty2023Member_b65a8d98-3045-47fd-b692-ee09e6d940e1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_d691053e-4ead-458e-99a5-5cee423862e5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_04af35df-8b20-4762-9c62-cd2ead5b7bf9" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_d691053e-4ead-458e-99a5-5cee423862e5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_d691053e-4ead-458e-99a5-5cee423862e5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_d691053e-4ead-458e-99a5-5cee423862e5" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_d691053e-4ead-458e-99a5-5cee423862e5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_ed08de30-7e2c-4df6-9af7-b4fb460928ef" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_d691053e-4ead-458e-99a5-5cee423862e5" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_ed08de30-7e2c-4df6-9af7-b4fb460928ef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsMember_1c99da7b-dc69-4f4b-8590-1eb1e7da04e1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_ed08de30-7e2c-4df6-9af7-b4fb460928ef" xlink:to="loc_us-gaap_OtherAssetsMember_1c99da7b-dc69-4f4b-8590-1eb1e7da04e1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesMember_42dea0ea-7698-4cec-b5e6-db5c12ab79e7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_ed08de30-7e2c-4df6-9af7-b4fb460928ef" xlink:to="loc_us-gaap_OtherLiabilitiesMember_42dea0ea-7698-4cec-b5e6-db5c12ab79e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_1a7ff8db-fba3-43a8-bbb1-0a2e1963a9c9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_04af35df-8b20-4762-9c62-cd2ead5b7bf9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_1a7ff8db-fba3-43a8-bbb1-0a2e1963a9c9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1a7ff8db-fba3-43a8-bbb1-0a2e1963a9c9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_1a7ff8db-fba3-43a8-bbb1-0a2e1963a9c9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1a7ff8db-fba3-43a8-bbb1-0a2e1963a9c9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_099803ad-f9f0-4a2c-9b44-141ae1230bc3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_1a7ff8db-fba3-43a8-bbb1-0a2e1963a9c9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_099803ad-f9f0-4a2c-9b44-141ae1230bc3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeasesAcquiredInPlaceMember_80e1aad0-1231-4aab-afc9-34edff78f9de" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LeasesAcquiredInPlaceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_099803ad-f9f0-4a2c-9b44-141ae1230bc3" xlink:to="loc_us-gaap_LeasesAcquiredInPlaceMember_80e1aad0-1231-4aab-afc9-34edff78f9de" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AboveMarketLeasesMember_a318778b-57d1-461b-88d1-baadcd791231" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AboveMarketLeasesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_099803ad-f9f0-4a2c-9b44-141ae1230bc3" xlink:to="loc_us-gaap_AboveMarketLeasesMember_a318778b-57d1-461b-88d1-baadcd791231" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_b987a54b-e47a-4ea0-b3e1-3e0231ad0dbc" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_04af35df-8b20-4762-9c62-cd2ead5b7bf9" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_b987a54b-e47a-4ea0-b3e1-3e0231ad0dbc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_b987a54b-e47a-4ea0-b3e1-3e0231ad0dbc_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_b987a54b-e47a-4ea0-b3e1-3e0231ad0dbc" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_b987a54b-e47a-4ea0-b3e1-3e0231ad0dbc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_4ce9bcab-9d1d-463b-a1d8-87b6c45ec8e4" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_b987a54b-e47a-4ea0-b3e1-3e0231ad0dbc" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_4ce9bcab-9d1d-463b-a1d8-87b6c45ec8e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_EscondidoPromenadeMember_0cf8c23c-4b97-4963-b496-6334e02d3724" xlink:href="frt-20230630.xsd#frt_EscondidoPromenadeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_4ce9bcab-9d1d-463b-a1d8-87b6c45ec8e4" xlink:to="loc_frt_EscondidoPromenadeMember_0cf8c23c-4b97-4963-b496-6334e02d3724" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_a5a4eb8c-763b-4d51-91e6-a1635031d15b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityInterestIssuedOrIssuableByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_04af35df-8b20-4762-9c62-cd2ead5b7bf9" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_a5a4eb8c-763b-4d51-91e6-a1635031d15b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_a5a4eb8c-763b-4d51-91e6-a1635031d15b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityInterestIssuedOrIssuableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_a5a4eb8c-763b-4d51-91e6-a1635031d15b" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_a5a4eb8c-763b-4d51-91e6-a1635031d15b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_12835ac8-e02d-4d96-8e49-c287c86f3bd1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityInterestIssuedOrIssuableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_a5a4eb8c-763b-4d51-91e6-a1635031d15b" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_12835ac8-e02d-4d96-8e49-c287c86f3bd1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_TICInterestMember_6ad6124b-2754-4056-8dfa-c3e7ff0d75ee" xlink:href="frt-20230630.xsd#frt_TICInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_12835ac8-e02d-4d96-8e49-c287c86f3bd1" xlink:to="loc_frt_TICInterestMember_6ad6124b-2754-4056-8dfa-c3e7ff0d75ee" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/DebtDetails" xlink:type="simple" xlink:href="frt-20230630.xsd#DebtDetails"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/DebtDetails" xlink:type="extended" id="if49327f642c7468db462599e9f5ce245_DebtDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_03fcfe24-7d1c-4708-88ed-088b3c3945e6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfDebt_d57400a9-3346-4318-872a-0bfa7807e9b0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_03fcfe24-7d1c-4708-88ed-088b3c3945e6" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfDebt_d57400a9-3346-4318-872a-0bfa7807e9b0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_bf50bd94-84ce-4b5e-b1c7-57333a994769" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_03fcfe24-7d1c-4708-88ed-088b3c3945e6" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_bf50bd94-84ce-4b5e-b1c7-57333a994769" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_NoteOfferingPercent_419b3da4-b0e3-48db-b798-4ef2f31003ca" xlink:href="frt-20230630.xsd#frt_NoteOfferingPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_03fcfe24-7d1c-4708-88ed-088b3c3945e6" xlink:to="loc_frt_NoteOfferingPercent_419b3da4-b0e3-48db-b798-4ef2f31003ca" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_DebtInstrumentYieldToMaturity_4b00d6fa-6b85-4aab-a09a-7c5a11cc90a1" xlink:href="frt-20230630.xsd#frt_DebtInstrumentYieldToMaturity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_03fcfe24-7d1c-4708-88ed-088b3c3945e6" xlink:to="loc_frt_DebtInstrumentYieldToMaturity_4b00d6fa-6b85-4aab-a09a-7c5a11cc90a1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDebtNetOfIssuanceCosts_9f136273-3398-4654-99c2-8418ae62057e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromDebtNetOfIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_03fcfe24-7d1c-4708-88ed-088b3c3945e6" xlink:to="loc_us-gaap_ProceedsFromDebtNetOfIssuanceCosts_9f136273-3398-4654-99c2-8418ae62057e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfUnsecuredDebt_897a083c-0caa-4fe0-b999-8d30f82f364e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RepaymentsOfUnsecuredDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_03fcfe24-7d1c-4708-88ed-088b3c3945e6" xlink:to="loc_us-gaap_RepaymentsOfUnsecuredDebt_897a083c-0caa-4fe0-b999-8d30f82f364e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_bcbe824f-cb9f-4a05-89d7-0ce57fd9976a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_03fcfe24-7d1c-4708-88ed-088b3c3945e6" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_bcbe824f-cb9f-4a05-89d7-0ce57fd9976a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod_be884bdb-509b-428f-bb66-1b03d7d3643c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_03fcfe24-7d1c-4708-88ed-088b3c3945e6" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod_be884bdb-509b-428f-bb66-1b03d7d3643c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityAverageOutstandingAmount_6023ba56-57e5-4c92-bad2-abb1d2b0ae8c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityAverageOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_03fcfe24-7d1c-4708-88ed-088b3c3945e6" xlink:to="loc_us-gaap_LineOfCreditFacilityAverageOutstandingAmount_6023ba56-57e5-4c92-bad2-abb1d2b0ae8c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_LineofcreditfacilityweightedaverageinterestratebeforeamortizationofdebtFees_dfe26a3a-54c7-44ed-a7f4-a9ef4afebac9" xlink:href="frt-20230630.xsd#frt_LineofcreditfacilityweightedaverageinterestratebeforeamortizationofdebtFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_03fcfe24-7d1c-4708-88ed-088b3c3945e6" xlink:to="loc_frt_LineofcreditfacilityweightedaverageinterestratebeforeamortizationofdebtFees_dfe26a3a-54c7-44ed-a7f4-a9ef4afebac9" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_bc5edc6b-ce90-4de0-9ee9-794fac1ffe43" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_03fcfe24-7d1c-4708-88ed-088b3c3945e6" xlink:to="loc_us-gaap_LineOfCredit_bc5edc6b-ce90-4de0-9ee9-794fac1ffe43" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_b6fd547b-a647-4046-9dd5-7c0eba0c5839" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_03fcfe24-7d1c-4708-88ed-088b3c3945e6" xlink:to="loc_us-gaap_DebtInstrumentTable_b6fd547b-a647-4046-9dd5-7c0eba0c5839" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_ae21535c-9368-40c3-9821-37a8f5c0a72d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_b6fd547b-a647-4046-9dd5-7c0eba0c5839" xlink:to="loc_us-gaap_DebtInstrumentAxis_ae21535c-9368-40c3-9821-37a8f5c0a72d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_ae21535c-9368-40c3-9821-37a8f5c0a72d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_ae21535c-9368-40c3-9821-37a8f5c0a72d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_ae21535c-9368-40c3-9821-37a8f5c0a72d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_e348862e-5255-4d42-81c7-1187ad525a41" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_ae21535c-9368-40c3-9821-37a8f5c0a72d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_e348862e-5255-4d42-81c7-1187ad525a41" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_Senior5Point375PercentNotesMember_84837668-39ff-430d-91a7-4217f0f65f94" xlink:href="frt-20230630.xsd#frt_Senior5Point375PercentNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_e348862e-5255-4d42-81c7-1187ad525a41" xlink:to="loc_frt_Senior5Point375PercentNotesMember_84837668-39ff-430d-91a7-4217f0f65f94" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_Senior2Point75PercentNotesMember_15052e1c-8de9-4508-8221-fc292defe358" xlink:href="frt-20230630.xsd#frt_Senior2Point75PercentNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_e348862e-5255-4d42-81c7-1187ad525a41" xlink:to="loc_frt_Senior2Point75PercentNotesMember_15052e1c-8de9-4508-8221-fc292defe358" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_2b7d5e51-6d8b-4bab-98ea-9e9a7e13db76" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_e348862e-5255-4d42-81c7-1187ad525a41" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_2b7d5e51-6d8b-4bab-98ea-9e9a7e13db76" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_28f6c271-fe52-4ac8-89ab-710d9df0e4e4" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_b6fd547b-a647-4046-9dd5-7c0eba0c5839" xlink:to="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_28f6c271-fe52-4ac8-89ab-710d9df0e4e4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_28f6c271-fe52-4ac8-89ab-710d9df0e4e4_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_28f6c271-fe52-4ac8-89ab-710d9df0e4e4" xlink:to="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_28f6c271-fe52-4ac8-89ab-710d9df0e4e4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_26e03c83-eca5-488c-b76d-7744d7cdf0ba" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_28f6c271-fe52-4ac8-89ab-710d9df0e4e4" xlink:to="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_26e03c83-eca5-488c-b76d-7744d7cdf0ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_bfc807f2-4175-4524-8865-38ed5d3533e4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_b6fd547b-a647-4046-9dd5-7c0eba0c5839" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_bfc807f2-4175-4524-8865-38ed5d3533e4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_bfc807f2-4175-4524-8865-38ed5d3533e4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_bfc807f2-4175-4524-8865-38ed5d3533e4" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_bfc807f2-4175-4524-8865-38ed5d3533e4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_f4a70a05-6d47-4640-b7e3-6552078e66f8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_bfc807f2-4175-4524-8865-38ed5d3533e4" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_f4a70a05-6d47-4640-b7e3-6552078e66f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_99b868d8-e319-4acc-bd49-a42bec309f60" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_f4a70a05-6d47-4640-b7e3-6552078e66f8" xlink:to="loc_us-gaap_SeniorNotesMember_99b868d8-e319-4acc-bd49-a42bec309f60" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/FairValueofFinancialInstrumentsSummaryofCarryingValueandFairValueofFinancialInstrumentsDetails" xlink:type="simple" xlink:href="frt-20230630.xsd#FairValueofFinancialInstrumentsSummaryofCarryingValueandFairValueofFinancialInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/FairValueofFinancialInstrumentsSummaryofCarryingValueandFairValueofFinancialInstrumentsDetails" xlink:type="extended" id="i40af4db9fea84c8ca4a012a7a9ae1f65_FairValueofFinancialInstrumentsSummaryofCarryingValueandFairValueofFinancialInstrumentsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_9400b94a-787e-41e8-9aad-93019d76a641" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_0052070f-2062-414b-a89a-4a34950de1c7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_9400b94a-787e-41e8-9aad-93019d76a641" xlink:to="loc_us-gaap_LongTermDebtFairValue_0052070f-2062-414b-a89a-4a34950de1c7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_0e4485ed-6b64-4c62-94eb-7196322bd49b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_9400b94a-787e-41e8-9aad-93019d76a641" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_0e4485ed-6b64-4c62-94eb-7196322bd49b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_42cb4fc4-297e-4fde-9d28-b534d7f0f415" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_0e4485ed-6b64-4c62-94eb-7196322bd49b" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_42cb4fc4-297e-4fde-9d28-b534d7f0f415" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_42cb4fc4-297e-4fde-9d28-b534d7f0f415_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_42cb4fc4-297e-4fde-9d28-b534d7f0f415" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_42cb4fc4-297e-4fde-9d28-b534d7f0f415_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_a892fe40-21a2-4a13-ad1c-b695c9f10fce" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_42cb4fc4-297e-4fde-9d28-b534d7f0f415" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_a892fe40-21a2-4a13-ad1c-b695c9f10fce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_MortgagesPayableAndNotesPayableMember_858ef334-aefc-4084-ad96-864ff5e22575" xlink:href="frt-20230630.xsd#frt_MortgagesPayableAndNotesPayableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_a892fe40-21a2-4a13-ad1c-b695c9f10fce" xlink:to="loc_frt_MortgagesPayableAndNotesPayableMember_858ef334-aefc-4084-ad96-864ff5e22575" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_SeniorNotesAndDebenturesMember_654d8cca-20f2-4c2f-a5a8-eab58a955f61" xlink:href="frt-20230630.xsd#frt_SeniorNotesAndDebenturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_a892fe40-21a2-4a13-ad1c-b695c9f10fce" xlink:to="loc_frt_SeniorNotesAndDebenturesMember_654d8cca-20f2-4c2f-a5a8-eab58a955f61" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_a67ea27c-3b4e-4a16-8d78-168678cb7bf5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_0e4485ed-6b64-4c62-94eb-7196322bd49b" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_a67ea27c-3b4e-4a16-8d78-168678cb7bf5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_a67ea27c-3b4e-4a16-8d78-168678cb7bf5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_a67ea27c-3b4e-4a16-8d78-168678cb7bf5" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_a67ea27c-3b4e-4a16-8d78-168678cb7bf5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_caae0157-6284-437a-a2a3-9bfd1ba3ef2f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_a67ea27c-3b4e-4a16-8d78-168678cb7bf5" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_caae0157-6284-437a-a2a3-9bfd1ba3ef2f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_d46f7d0e-1260-45f9-94e3-d9d3aaf49b79" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_caae0157-6284-437a-a2a3-9bfd1ba3ef2f" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_d46f7d0e-1260-45f9-94e3-d9d3aaf49b79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_60ef3a57-7692-43b3-aeaa-9200517cdcba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_d46f7d0e-1260-45f9-94e3-d9d3aaf49b79" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_60ef3a57-7692-43b3-aeaa-9200517cdcba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_528a6bd9-e0fe-4934-8c1e-15ad73dc26d8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_d46f7d0e-1260-45f9-94e3-d9d3aaf49b79" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_528a6bd9-e0fe-4934-8c1e-15ad73dc26d8" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/FairValueOfFinancialInstrumentsDetails" xlink:type="simple" xlink:href="frt-20230630.xsd#FairValueOfFinancialInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/FairValueOfFinancialInstrumentsDetails" xlink:type="extended" id="ifdba9ca6a5a44a2c8add3222851a2417_FairValueOfFinancialInstrumentsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_a7eab1ce-42ba-4823-ab98-d04171dc4d42" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfInterestRateDerivativesHeld_7f914b1c-15fb-4f9f-94be-7019d97b787a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NumberOfInterestRateDerivativesHeld"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_a7eab1ce-42ba-4823-ab98-d04171dc4d42" xlink:to="loc_us-gaap_NumberOfInterestRateDerivativesHeld_7f914b1c-15fb-4f9f-94be-7019d97b787a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_c5de09e2-fea9-460a-92f0-363905aafcd9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_a7eab1ce-42ba-4823-ab98-d04171dc4d42" xlink:to="loc_us-gaap_DerivativeNotionalAmount_c5de09e2-fea9-460a-92f0-363905aafcd9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_a268cec0-5553-4a46-bae5-7c418da1286e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_a7eab1ce-42ba-4823-ab98-d04171dc4d42" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_a268cec0-5553-4a46-bae5-7c418da1286e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFixedInterestRate_a2b5a035-3b84-496a-8545-f5a552fa81c2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeFixedInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_a7eab1ce-42ba-4823-ab98-d04171dc4d42" xlink:to="loc_us-gaap_DerivativeFixedInterestRate_a2b5a035-3b84-496a-8545-f5a552fa81c2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_4161b41b-3bf8-4996-9fb2-6e11e7115ec7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_a7eab1ce-42ba-4823-ab98-d04171dc4d42" xlink:to="loc_us-gaap_DerivativeAssets_4161b41b-3bf8-4996-9fb2-6e11e7115ec7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_33744d8c-b2c8-4488-ab72-8dabb6ff1e9f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_a7eab1ce-42ba-4823-ab98-d04171dc4d42" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_33744d8c-b2c8-4488-ab72-8dabb6ff1e9f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet_97eb8339-4070-470a-ba4a-32990065a736" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_a7eab1ce-42ba-4823-ab98-d04171dc4d42" xlink:to="loc_us-gaap_InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet_97eb8339-4070-470a-ba4a-32990065a736" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_5a3fb20f-1342-4652-85d9-b111014741c8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_a7eab1ce-42ba-4823-ab98-d04171dc4d42" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_5a3fb20f-1342-4652-85d9-b111014741c8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4de6a1b8-2cc9-4198-98a2-a6cc94213d0b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_5a3fb20f-1342-4652-85d9-b111014741c8" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4de6a1b8-2cc9-4198-98a2-a6cc94213d0b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4de6a1b8-2cc9-4198-98a2-a6cc94213d0b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4de6a1b8-2cc9-4198-98a2-a6cc94213d0b" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4de6a1b8-2cc9-4198-98a2-a6cc94213d0b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_794f87cb-4a77-482e-999f-36e464b8324d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4de6a1b8-2cc9-4198-98a2-a6cc94213d0b" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_794f87cb-4a77-482e-999f-36e464b8324d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_3d171c72-cc33-4ee5-bffc-24316b43924d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_794f87cb-4a77-482e-999f-36e464b8324d" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_3d171c72-cc33-4ee5-bffc-24316b43924d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_3a95273c-eae4-40b3-80c3-2b28ea3d2421" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_794f87cb-4a77-482e-999f-36e464b8324d" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_3a95273c-eae4-40b3-80c3-2b28ea3d2421" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_a65d236a-c03e-4e68-8bfe-0881e51586ff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_794f87cb-4a77-482e-999f-36e464b8324d" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_a65d236a-c03e-4e68-8bfe-0881e51586ff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_5d1b31ff-33c6-4872-9774-07a64b26afd3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_5a3fb20f-1342-4652-85d9-b111014741c8" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_5d1b31ff-33c6-4872-9774-07a64b26afd3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_5d1b31ff-33c6-4872-9774-07a64b26afd3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_5d1b31ff-33c6-4872-9774-07a64b26afd3" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_5d1b31ff-33c6-4872-9774-07a64b26afd3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_5a34cb46-6e80-4fa5-9a9f-39a6325500fd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_5d1b31ff-33c6-4872-9774-07a64b26afd3" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_5a34cb46-6e80-4fa5-9a9f-39a6325500fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MortgagesMember_e64c4058-e44c-4fb9-aedf-d95f655a3587" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MortgagesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_5a34cb46-6e80-4fa5-9a9f-39a6325500fd" xlink:to="loc_us-gaap_MortgagesMember_e64c4058-e44c-4fb9-aedf-d95f655a3587" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_87a4de07-ef0c-4e1c-9173-4991b5d2e3c6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_5a34cb46-6e80-4fa5-9a9f-39a6325500fd" xlink:to="loc_us-gaap_SecuredDebtMember_87a4de07-ef0c-4e1c-9173-4991b5d2e3c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_49ba9ce9-cabc-4e3f-9202-d3e337d1fa6e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_5a3fb20f-1342-4652-85d9-b111014741c8" xlink:to="loc_us-gaap_DebtInstrumentAxis_49ba9ce9-cabc-4e3f-9202-d3e337d1fa6e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_49ba9ce9-cabc-4e3f-9202-d3e337d1fa6e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_49ba9ce9-cabc-4e3f-9202-d3e337d1fa6e" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_49ba9ce9-cabc-4e3f-9202-d3e337d1fa6e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_2f8b7eed-61b5-4e2e-b808-47a844ad7727" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_49ba9ce9-cabc-4e3f-9202-d3e337d1fa6e" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_2f8b7eed-61b5-4e2e-b808-47a844ad7727" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_HobokenMember_42f46e86-327d-49ab-a9be-fd1d86f8d8f8" xlink:href="frt-20230630.xsd#frt_HobokenMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_2f8b7eed-61b5-4e2e-b808-47a844ad7727" xlink:to="loc_frt_HobokenMember_42f46e86-327d-49ab-a9be-fd1d86f8d8f8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_75b2b4b2-ba2d-4210-aa64-aa6aee97ae5c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_5a3fb20f-1342-4652-85d9-b111014741c8" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_75b2b4b2-ba2d-4210-aa64-aa6aee97ae5c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_75b2b4b2-ba2d-4210-aa64-aa6aee97ae5c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_75b2b4b2-ba2d-4210-aa64-aa6aee97ae5c" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_75b2b4b2-ba2d-4210-aa64-aa6aee97ae5c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_50bcd523-0ada-44e0-b65b-9bf59b65f7cd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_75b2b4b2-ba2d-4210-aa64-aa6aee97ae5c" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_50bcd523-0ada-44e0-b65b-9bf59b65f7cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_9ffcf40c-5d7f-498e-a9e3-030b19e1113c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_50bcd523-0ada-44e0-b65b-9bf59b65f7cd" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_9ffcf40c-5d7f-498e-a9e3-030b19e1113c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_4de96684-7f26-4d43-adc8-8c8cd2d20fe7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_5a3fb20f-1342-4652-85d9-b111014741c8" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_4de96684-7f26-4d43-adc8-8c8cd2d20fe7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_4de96684-7f26-4d43-adc8-8c8cd2d20fe7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_4de96684-7f26-4d43-adc8-8c8cd2d20fe7" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_4de96684-7f26-4d43-adc8-8c8cd2d20fe7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_3cc8acfb-92cb-4aee-b845-d9cb52b9fb8c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_4de96684-7f26-4d43-adc8-8c8cd2d20fe7" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_3cc8acfb-92cb-4aee-b845-d9cb52b9fb8c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_7861eb9b-31a4-4716-b1e7-f7dc12213251" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_3cc8acfb-92cb-4aee-b845-d9cb52b9fb8c" xlink:to="loc_us-gaap_InterestRateSwapMember_7861eb9b-31a4-4716-b1e7-f7dc12213251" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_864551e3-d8d5-41d5-a252-b30d31411300" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_5a3fb20f-1342-4652-85d9-b111014741c8" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_864551e3-d8d5-41d5-a252-b30d31411300" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_864551e3-d8d5-41d5-a252-b30d31411300_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_864551e3-d8d5-41d5-a252-b30d31411300" xlink:to="loc_us-gaap_EquityComponentDomain_864551e3-d8d5-41d5-a252-b30d31411300_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_5c51f7af-2604-4013-9c5f-431d2547087d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_864551e3-d8d5-41d5-a252-b30d31411300" xlink:to="loc_us-gaap_EquityComponentDomain_5c51f7af-2604-4013-9c5f-431d2547087d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_458cf1f7-b3f9-48c9-b392-3028bc65f276" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5c51f7af-2604-4013-9c5f-431d2547087d" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_458cf1f7-b3f9-48c9-b392-3028bc65f276" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_dab48e96-75f3-49ac-946c-52190e90d4d6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_5a3fb20f-1342-4652-85d9-b111014741c8" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_dab48e96-75f3-49ac-946c-52190e90d4d6" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_dab48e96-75f3-49ac-946c-52190e90d4d6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_dab48e96-75f3-49ac-946c-52190e90d4d6" xlink:to="loc_us-gaap_RelatedPartyDomain_dab48e96-75f3-49ac-946c-52190e90d4d6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_9f98858c-5865-4ce8-939e-93bee96bbddd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_dab48e96-75f3-49ac-946c-52190e90d4d6" xlink:to="loc_us-gaap_RelatedPartyDomain_9f98858c-5865-4ce8-939e-93bee96bbddd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvesteeMember_bfe2cade-a6a3-4991-8601-70dd372a70e1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityMethodInvesteeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_9f98858c-5865-4ce8-939e-93bee96bbddd" xlink:to="loc_us-gaap_EquityMethodInvesteeMember_bfe2cade-a6a3-4991-8601-70dd372a70e1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/CommitmentsandContingenciesDetails" xlink:type="simple" xlink:href="frt-20230630.xsd#CommitmentsandContingenciesDetails"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/CommitmentsandContingenciesDetails" xlink:type="extended" id="i05dc36b4d7de40868a9c1841f0809651_CommitmentsandContingenciesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsLineItems_fb1e87ff-c592-491e-8a1d-b8e4996c9823" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherCommitmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalAccountUnits_cb1cd7dc-0851-44f6-8a6a-ae57447118e3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalAccountUnits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_fb1e87ff-c592-491e-8a1d-b8e4996c9823" xlink:to="loc_us-gaap_PartnersCapitalAccountUnits_cb1cd7dc-0851-44f6-8a6a-ae57447118e3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_OperatingPartnershipUnitsFairValue_d01723b1-57ad-4723-a2db-07edb27826cd" xlink:href="frt-20230630.xsd#frt_OperatingPartnershipUnitsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_fb1e87ff-c592-491e-8a1d-b8e4996c9823" xlink:to="loc_frt_OperatingPartnershipUnitsFairValue_d01723b1-57ad-4723-a2db-07edb27826cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsTable_d4f464c6-47ed-4280-8b71-4c0343bcddf8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherCommitmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_fb1e87ff-c592-491e-8a1d-b8e4996c9823" xlink:to="loc_us-gaap_OtherCommitmentsTable_d4f464c6-47ed-4280-8b71-4c0343bcddf8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ConvertibleUnitTypeAxis_cc1fc42f-c167-4964-bda2-e5c7c081c0f9" xlink:href="frt-20230630.xsd#frt_ConvertibleUnitTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_d4f464c6-47ed-4280-8b71-4c0343bcddf8" xlink:to="loc_frt_ConvertibleUnitTypeAxis_cc1fc42f-c167-4964-bda2-e5c7c081c0f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ConvertibleUnitTypeDomain_cc1fc42f-c167-4964-bda2-e5c7c081c0f9_default" xlink:href="frt-20230630.xsd#frt_ConvertibleUnitTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_frt_ConvertibleUnitTypeAxis_cc1fc42f-c167-4964-bda2-e5c7c081c0f9" xlink:to="loc_frt_ConvertibleUnitTypeDomain_cc1fc42f-c167-4964-bda2-e5c7c081c0f9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ConvertibleUnitTypeDomain_7474114c-8620-40a6-a090-e0804fbfc469" xlink:href="frt-20230630.xsd#frt_ConvertibleUnitTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_frt_ConvertibleUnitTypeAxis_cc1fc42f-c167-4964-bda2-e5c7c081c0f9" xlink:to="loc_frt_ConvertibleUnitTypeDomain_7474114c-8620-40a6-a090-e0804fbfc469" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_DownREITOPUnitsMember_d80f494a-b8cd-4837-8605-bfa3c10578d4" xlink:href="frt-20230630.xsd#frt_DownREITOPUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_ConvertibleUnitTypeDomain_7474114c-8620-40a6-a090-e0804fbfc469" xlink:to="loc_frt_DownREITOPUnitsMember_d80f494a-b8cd-4837-8605-bfa3c10578d4" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/ShareholdersEquitySummaryofDividendsDetails" xlink:type="simple" xlink:href="frt-20230630.xsd#ShareholdersEquitySummaryofDividendsDetails"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ShareholdersEquitySummaryofDividendsDetails" xlink:type="extended" id="i63b29e9ace84414283b5bd33c1c51e76_ShareholdersEquitySummaryofDividendsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableLineItems_94019292-5246-4103-9758-8566a0f6813f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DividendsPayableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_a24689cb-6575-4006-a60c-cf08a2f5a262" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsPayableLineItems_94019292-5246-4103-9758-8566a0f6813f" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_a24689cb-6575-4006-a60c-cf08a2f5a262" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareCashPaid_32cfb2ec-e936-4ad9-a098-5184aa9f6a30" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockDividendsPerShareCashPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsPayableLineItems_94019292-5246-4103-9758-8566a0f6813f" xlink:to="loc_us-gaap_CommonStockDividendsPerShareCashPaid_32cfb2ec-e936-4ad9-a098-5184aa9f6a30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendsPerShareDeclared_7689a51e-fac0-4617-a0b7-de1823420ff0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsPayableLineItems_94019292-5246-4103-9758-8566a0f6813f" xlink:to="loc_us-gaap_PreferredStockDividendsPerShareDeclared_7689a51e-fac0-4617-a0b7-de1823420ff0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendsPerShareCashPaid_845775db-2cc8-44eb-bbc1-c4c2b5de67ae" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockDividendsPerShareCashPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsPayableLineItems_94019292-5246-4103-9758-8566a0f6813f" xlink:to="loc_us-gaap_PreferredStockDividendsPerShareCashPaid_845775db-2cc8-44eb-bbc1-c4c2b5de67ae" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableTable_b5f55c9d-125a-4079-b21d-0a1a39d79ddc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DividendsPayableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DividendsPayableLineItems_94019292-5246-4103-9758-8566a0f6813f" xlink:to="loc_us-gaap_DividendsPayableTable_b5f55c9d-125a-4079-b21d-0a1a39d79ddc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_93744faa-b3ce-44c0-a1be-f19160f2b9e2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DividendsPayableTable_b5f55c9d-125a-4079-b21d-0a1a39d79ddc" xlink:to="loc_us-gaap_StatementClassOfStockAxis_93744faa-b3ce-44c0-a1be-f19160f2b9e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_93744faa-b3ce-44c0-a1be-f19160f2b9e2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_93744faa-b3ce-44c0-a1be-f19160f2b9e2" xlink:to="loc_us-gaap_ClassOfStockDomain_93744faa-b3ce-44c0-a1be-f19160f2b9e2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_204b024b-9e51-4a85-91a8-98ce29e57cc7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_93744faa-b3ce-44c0-a1be-f19160f2b9e2" xlink:to="loc_us-gaap_ClassOfStockDomain_204b024b-9e51-4a85-91a8-98ce29e57cc7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_A5417Series1CumulativeConvertiblePreferredMember_3477a000-1458-4a95-9744-3eb2cc6f3356" xlink:href="frt-20230630.xsd#frt_A5417Series1CumulativeConvertiblePreferredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_204b024b-9e51-4a85-91a8-98ce29e57cc7" xlink:to="loc_frt_A5417Series1CumulativeConvertiblePreferredMember_3477a000-1458-4a95-9744-3eb2cc6f3356" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_A5.0SeriesCCumulativeRedeemablePreferredMember_a86d9e08-b574-4a47-9cc6-aefe5e6ea1a8" xlink:href="frt-20230630.xsd#frt_A5.0SeriesCCumulativeRedeemablePreferredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_204b024b-9e51-4a85-91a8-98ce29e57cc7" xlink:to="loc_frt_A5.0SeriesCCumulativeRedeemablePreferredMember_a86d9e08-b574-4a47-9cc6-aefe5e6ea1a8" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/ShareholdersEquityNarrativeDetails" xlink:type="simple" xlink:href="frt-20230630.xsd#ShareholdersEquityNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ShareholdersEquityNarrativeDetails" xlink:type="extended" id="i405042fc31d54566a82ba9ab3f1e7be9_ShareholdersEquityNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_650aac62-cb89-4b15-b6b3-3eea66e56ca9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_AggregateOfferingPriceOfCommonShare_9780d232-c937-43fc-8ba2-00e92eab4394" xlink:href="frt-20230630.xsd#frt_AggregateOfferingPriceOfCommonShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_650aac62-cb89-4b15-b6b3-3eea66e56ca9" xlink:to="loc_frt_AggregateOfferingPriceOfCommonShare_9780d232-c937-43fc-8ba2-00e92eab4394" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_7e8da275-2fa8-4df6-a043-b928b25da046" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_650aac62-cb89-4b15-b6b3-3eea66e56ca9" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_7e8da275-2fa8-4df6-a043-b928b25da046" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_WeightedAveragePricePerCommonShare_1d17bedb-15e5-4899-ac33-db5fc239fbaa" xlink:href="frt-20230630.xsd#frt_WeightedAveragePricePerCommonShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_650aac62-cb89-4b15-b6b3-3eea66e56ca9" xlink:to="loc_frt_WeightedAveragePricePerCommonShare_1d17bedb-15e5-4899-ac33-db5fc239fbaa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_5694ce5e-451f-4378-bcf1-8f87ab6a409f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_650aac62-cb89-4b15-b6b3-3eea66e56ca9" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_5694ce5e-451f-4378-bcf1-8f87ab6a409f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfStockIssuanceCosts_0e3723ca-2368-4232-a705-a4608c18bd87" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsOfStockIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_650aac62-cb89-4b15-b6b3-3eea66e56ca9" xlink:to="loc_us-gaap_PaymentsOfStockIssuanceCosts_0e3723ca-2368-4232-a705-a4608c18bd87" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_RemainingCapacityToIssue_b4080e76-7757-49b6-8fef-d41a091226a0" xlink:href="frt-20230630.xsd#frt_RemainingCapacityToIssue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_650aac62-cb89-4b15-b6b3-3eea66e56ca9" xlink:to="loc_frt_RemainingCapacityToIssue_b4080e76-7757-49b6-8fef-d41a091226a0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_6ee72b81-faf0-4f64-bc93-563821dbb507" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_650aac62-cb89-4b15-b6b3-3eea66e56ca9" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_6ee72b81-faf0-4f64-bc93-563821dbb507" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_c61ed5c2-5d5c-49e3-9d3f-8dcb00c52789" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_650aac62-cb89-4b15-b6b3-3eea66e56ca9" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_c61ed5c2-5d5c-49e3-9d3f-8dcb00c52789" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_05a95c6d-7289-406d-b86e-155a81602a2b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_c61ed5c2-5d5c-49e3-9d3f-8dcb00c52789" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_05a95c6d-7289-406d-b86e-155a81602a2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_05a95c6d-7289-406d-b86e-155a81602a2b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_05a95c6d-7289-406d-b86e-155a81602a2b" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_05a95c6d-7289-406d-b86e-155a81602a2b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_fda3c210-7778-4c30-90a3-f0a259842434" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_05a95c6d-7289-406d-b86e-155a81602a2b" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_fda3c210-7778-4c30-90a3-f0a259842434" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_AtMarketEquityProgramMember_bfcfb97e-7747-4d23-831c-25048c1c46fd" xlink:href="frt-20230630.xsd#frt_AtMarketEquityProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_fda3c210-7778-4c30-90a3-f0a259842434" xlink:to="loc_frt_AtMarketEquityProgramMember_bfcfb97e-7747-4d23-831c-25048c1c46fd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_StockIssuanceCostsByTypeAxis_63f6cad2-0ae9-4209-847d-504d50551fdf" xlink:href="frt-20230630.xsd#frt_StockIssuanceCostsByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_c61ed5c2-5d5c-49e3-9d3f-8dcb00c52789" xlink:to="loc_frt_StockIssuanceCostsByTypeAxis_63f6cad2-0ae9-4209-847d-504d50551fdf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_StockIssuanceCostsByTypeDomain_63f6cad2-0ae9-4209-847d-504d50551fdf_default" xlink:href="frt-20230630.xsd#frt_StockIssuanceCostsByTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_frt_StockIssuanceCostsByTypeAxis_63f6cad2-0ae9-4209-847d-504d50551fdf" xlink:to="loc_frt_StockIssuanceCostsByTypeDomain_63f6cad2-0ae9-4209-847d-504d50551fdf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_StockIssuanceCostsByTypeDomain_dac07745-e773-4528-bf3b-943ade7b571c" xlink:href="frt-20230630.xsd#frt_StockIssuanceCostsByTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_frt_StockIssuanceCostsByTypeAxis_63f6cad2-0ae9-4209-847d-504d50551fdf" xlink:to="loc_frt_StockIssuanceCostsByTypeDomain_dac07745-e773-4528-bf3b-943ade7b571c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_CommissionsMember_ca567e19-820d-48bb-a405-da5d55ca40d1" xlink:href="frt-20230630.xsd#frt_CommissionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_StockIssuanceCostsByTypeDomain_dac07745-e773-4528-bf3b-943ade7b571c" xlink:to="loc_frt_CommissionsMember_ca567e19-820d-48bb-a405-da5d55ca40d1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_OtherOfferingCostsMember_9fa51440-0a0d-4935-883b-584d2aeafd4c" xlink:href="frt-20230630.xsd#frt_OtherOfferingCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_StockIssuanceCostsByTypeDomain_dac07745-e773-4528-bf3b-943ade7b571c" xlink:to="loc_frt_OtherOfferingCostsMember_9fa51440-0a0d-4935-883b-584d2aeafd4c" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/EarningsPerShareAndUnitDetails" xlink:type="simple" xlink:href="frt-20230630.xsd#EarningsPerShareAndUnitDetails"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/EarningsPerShareAndUnitDetails" xlink:type="extended" id="i912d8d0dcfc24842ab5574f3900e5eee_EarningsPerShareAndUnitDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_43ffd9e4-9e4e-4552-9d5d-922bc118b210" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToParticipatingNonvestedSharesWithNonForfeitableDividendRights_f8e48ee9-ef77-4d91-9e7f-da3404994c48" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncrementalCommonSharesAttributableToParticipatingNonvestedSharesWithNonForfeitableDividendRights"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_43ffd9e4-9e4e-4552-9d5d-922bc118b210" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToParticipatingNonvestedSharesWithNonForfeitableDividendRights_f8e48ee9-ef77-4d91-9e7f-da3404994c48" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_IncrementalCommonUnitsAttributableToParticipatingNonvestedShares_3c45a385-14a6-4e1e-b912-3eda1e1e5350" xlink:href="frt-20230630.xsd#frt_IncrementalCommonUnitsAttributableToParticipatingNonvestedShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_43ffd9e4-9e4e-4552-9d5d-922bc118b210" xlink:to="loc_frt_IncrementalCommonUnitsAttributableToParticipatingNonvestedShares_3c45a385-14a6-4e1e-b912-3eda1e1e5350" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_21a2f7dd-8104-4ca2-a4a6-f2a56bc52aaa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_43ffd9e4-9e4e-4552-9d5d-922bc118b210" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_21a2f7dd-8104-4ca2-a4a6-f2a56bc52aaa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_AntidilutiveSecuritiesExcludedFromComputationOfNetIncomePerOutstandingUnitUnits_b8e05aea-d640-4e61-8011-6332cdaa1d0f" xlink:href="frt-20230630.xsd#frt_AntidilutiveSecuritiesExcludedFromComputationOfNetIncomePerOutstandingUnitUnits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_43ffd9e4-9e4e-4552-9d5d-922bc118b210" xlink:to="loc_frt_AntidilutiveSecuritiesExcludedFromComputationOfNetIncomePerOutstandingUnitUnits_b8e05aea-d640-4e61-8011-6332cdaa1d0f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendRatePercentage_e1e2564f-4b48-46a2-82d2-62ed69c89536" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockDividendRatePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_43ffd9e4-9e4e-4552-9d5d-922bc118b210" xlink:to="loc_us-gaap_PreferredStockDividendRatePercentage_e1e2564f-4b48-46a2-82d2-62ed69c89536" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_PreferredUnitDistributionRatePercentage_d87c8b8c-4d19-42e0-bd9c-af1f55ce3e63" xlink:href="frt-20230630.xsd#frt_PreferredUnitDistributionRatePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_43ffd9e4-9e4e-4552-9d5d-922bc118b210" xlink:to="loc_frt_PreferredUnitDistributionRatePercentage_d87c8b8c-4d19-42e0-bd9c-af1f55ce3e63" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_b9d73c6f-9537-4fb8-9ebc-11436672c291" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_43ffd9e4-9e4e-4552-9d5d-922bc118b210" xlink:to="loc_us-gaap_StatementTable_b9d73c6f-9537-4fb8-9ebc-11436672c291" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ShareTypeAxis_b63be01c-c667-464c-89c6-6b7f70506ad0" xlink:href="frt-20230630.xsd#frt_ShareTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_b9d73c6f-9537-4fb8-9ebc-11436672c291" xlink:to="loc_frt_ShareTypeAxis_b63be01c-c667-464c-89c6-6b7f70506ad0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ShareTypeDomain_b63be01c-c667-464c-89c6-6b7f70506ad0_default" xlink:href="frt-20230630.xsd#frt_ShareTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_frt_ShareTypeAxis_b63be01c-c667-464c-89c6-6b7f70506ad0" xlink:to="loc_frt_ShareTypeDomain_b63be01c-c667-464c-89c6-6b7f70506ad0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ShareTypeDomain_d1d62a13-6cdb-4e18-8132-122acdb6d0d1" xlink:href="frt-20230630.xsd#frt_ShareTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_frt_ShareTypeAxis_b63be01c-c667-464c-89c6-6b7f70506ad0" xlink:to="loc_frt_ShareTypeDomain_d1d62a13-6cdb-4e18-8132-122acdb6d0d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_StockOptionsMember_b4e14d31-6e9d-4e02-be83-dfbf92825106" xlink:href="frt-20230630.xsd#frt_StockOptionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_ShareTypeDomain_d1d62a13-6cdb-4e18-8132-122acdb6d0d1" xlink:to="loc_frt_StockOptionsMember_b4e14d31-6e9d-4e02-be83-dfbf92825106" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ForwardSalesContractsMember_709631ed-bafe-42c7-815d-6fd134a66ea3" xlink:href="frt-20230630.xsd#frt_ForwardSalesContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_ShareTypeDomain_d1d62a13-6cdb-4e18-8132-122acdb6d0d1" xlink:to="loc_frt_ForwardSalesContractsMember_709631ed-bafe-42c7-815d-6fd134a66ea3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_PerformanceBasedUnvestedSharesMember_903a5b74-7cd6-40dc-90d8-910b98822f2b" xlink:href="frt-20230630.xsd#frt_PerformanceBasedUnvestedSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_ShareTypeDomain_d1d62a13-6cdb-4e18-8132-122acdb6d0d1" xlink:to="loc_frt_PerformanceBasedUnvestedSharesMember_903a5b74-7cd6-40dc-90d8-910b98822f2b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_70613d9d-c01e-4d07-a16d-e6e58901b24d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_b9d73c6f-9537-4fb8-9ebc-11436672c291" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_70613d9d-c01e-4d07-a16d-e6e58901b24d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_70613d9d-c01e-4d07-a16d-e6e58901b24d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_70613d9d-c01e-4d07-a16d-e6e58901b24d" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_70613d9d-c01e-4d07-a16d-e6e58901b24d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_e00d1563-61f5-48f1-8193-77dd91aaaee1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_70613d9d-c01e-4d07-a16d-e6e58901b24d" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_e00d1563-61f5-48f1-8193-77dd91aaaee1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_ForwardSalesContractsMember_c2fb1bf6-bf00-4f93-9e65-401a837ad645" xlink:href="frt-20230630.xsd#frt_ForwardSalesContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_e00d1563-61f5-48f1-8193-77dd91aaaee1" xlink:to="loc_frt_ForwardSalesContractsMember_c2fb1bf6-bf00-4f93-9e65-401a837ad645" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_b097efa3-b20f-4366-8e63-0a92c557aec9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_b9d73c6f-9537-4fb8-9ebc-11436672c291" xlink:to="loc_us-gaap_StatementClassOfStockAxis_b097efa3-b20f-4366-8e63-0a92c557aec9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_b097efa3-b20f-4366-8e63-0a92c557aec9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_b097efa3-b20f-4366-8e63-0a92c557aec9" xlink:to="loc_us-gaap_ClassOfStockDomain_b097efa3-b20f-4366-8e63-0a92c557aec9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_26e68a38-71fa-42ba-bd09-be718b63fe06" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_b097efa3-b20f-4366-8e63-0a92c557aec9" xlink:to="loc_us-gaap_ClassOfStockDomain_26e68a38-71fa-42ba-bd09-be718b63fe06" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_A5417Series1CumulativeConvertiblePreferredMember_6ab355ba-e2f8-4e10-b214-0a4c724ff764" xlink:href="frt-20230630.xsd#frt_A5417Series1CumulativeConvertiblePreferredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_26e68a38-71fa-42ba-bd09-be718b63fe06" xlink:to="loc_frt_A5417Series1CumulativeConvertiblePreferredMember_6ab355ba-e2f8-4e10-b214-0a4c724ff764" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_PreferredUnitsMember_c39fb67d-b272-4fd9-9c9a-7b89b7290fca" xlink:href="frt-20230630.xsd#frt_PreferredUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_26e68a38-71fa-42ba-bd09-be718b63fe06" xlink:to="loc_frt_PreferredUnitsMember_c39fb67d-b272-4fd9-9c9a-7b89b7290fca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_b04e94c8-0583-4da1-8e68-6afcd9417631" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_b9d73c6f-9537-4fb8-9ebc-11436672c291" xlink:to="loc_srt_ConsolidatedEntitiesAxis_b04e94c8-0583-4da1-8e68-6afcd9417631" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_b04e94c8-0583-4da1-8e68-6afcd9417631_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_b04e94c8-0583-4da1-8e68-6afcd9417631" xlink:to="loc_srt_ConsolidatedEntitiesDomain_b04e94c8-0583-4da1-8e68-6afcd9417631_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_f92eaccf-8e14-4044-ae0b-a0447991b42f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_b04e94c8-0583-4da1-8e68-6afcd9417631" xlink:to="loc_srt_ConsolidatedEntitiesDomain_f92eaccf-8e14-4044-ae0b-a0447991b42f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_PartnershipInterestMember_2641c2fd-36d0-4cad-be5f-db26e327b872" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_PartnershipInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_f92eaccf-8e14-4044-ae0b-a0447991b42f" xlink:to="loc_srt_PartnershipInterestMember_2641c2fd-36d0-4cad-be5f-db26e327b872" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.federalrealty.com/role/EarningsPerShareAndUnitScheduleOfEarningsPerShareDetails" xlink:type="simple" xlink:href="frt-20230630.xsd#EarningsPerShareAndUnitScheduleOfEarningsPerShareDetails"/>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/EarningsPerShareAndUnitScheduleOfEarningsPerShareDetails" xlink:type="extended" id="i0ed94d5024414001ab8b6943690dfb6e_EarningsPerShareAndUnitScheduleOfEarningsPerShareDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_0ca1fb0f-396d-4476-a9f9-e1df8ee6b4c3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_us-gaap_ProfitLoss_0ca1fb0f-396d-4476-a9f9-e1df8ee6b4c3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_92f0ab97-1c93-4f0d-90b5-e7590c38b401" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_92f0ab97-1c93-4f0d-90b5-e7590c38b401" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_DistributionsDeclaredToPreferredUnitHolders_de80a0c9-b5b0-4920-9548-68f2c5847747" xlink:href="frt-20230630.xsd#frt_DistributionsDeclaredToPreferredUnitHolders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_frt_DistributionsDeclaredToPreferredUnitHolders_de80a0c9-b5b0-4920-9548-68f2c5847747" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_01470887-0d9e-4940-a67d-45d8462d05d9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_01470887-0d9e-4940-a67d-45d8462d05d9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_EarningsAllocatedToUnvestedShares_c58d38c1-e793-4fc4-b439-cfdbc76fe4fb" xlink:href="frt-20230630.xsd#frt_EarningsAllocatedToUnvestedShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_frt_EarningsAllocatedToUnvestedShares_c58d38c1-e793-4fc4-b439-cfdbc76fe4fb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_EarningsAllocatedToUnvestedUnits_3e563d39-de4f-4662-91a4-1277ac71657d" xlink:href="frt-20230630.xsd#frt_EarningsAllocatedToUnvestedUnits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_frt_EarningsAllocatedToUnvestedUnits_3e563d39-de4f-4662-91a4-1277ac71657d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_NetIncomeAvailableForCommonShareholdersBasicAndDiluted_5c864bcc-6ea6-418e-a7ee-e0c67d6754f2" xlink:href="frt-20230630.xsd#frt_NetIncomeAvailableForCommonShareholdersBasicAndDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_frt_NetIncomeAvailableForCommonShareholdersBasicAndDiluted_5c864bcc-6ea6-418e-a7ee-e0c67d6754f2" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_NetIncomeAvailableToCommonUnitHoldersBasicAndDiluted_91314e70-7530-451a-a228-2c8489e3ffe1" xlink:href="frt-20230630.xsd#frt_NetIncomeAvailableToCommonUnitHoldersBasicAndDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_frt_NetIncomeAvailableToCommonUnitHoldersBasicAndDiluted_91314e70-7530-451a-a228-2c8489e3ffe1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_f0a0f885-6c2d-4d9f-b341-66fd4e457525" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_f0a0f885-6c2d-4d9f-b341-66fd4e457525" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageLimitedPartnershipAndGeneralPartnershipUnitsOutstandingBasic_fb045ad3-c92d-45be-840a-986718572833" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageLimitedPartnershipAndGeneralPartnershipUnitsOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_us-gaap_WeightedAverageLimitedPartnershipAndGeneralPartnershipUnitsOutstandingBasic_fb045ad3-c92d-45be-840a-986718572833" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_7976d620-e530-429d-87c9-4ab9f62d67b3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_7976d620-e530-429d-87c9-4ab9f62d67b3" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_WeightedAverageNumberDilutedUnitsOutstandingAdjustment_982aecb0-e9d0-413a-98e5-94e2314ab349" xlink:href="frt-20230630.xsd#frt_WeightedAverageNumberDilutedUnitsOutstandingAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_frt_WeightedAverageNumberDilutedUnitsOutstandingAdjustment_982aecb0-e9d0-413a-98e5-94e2314ab349" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_adc55c6d-7bff-45cf-b84d-061789257b21" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_adc55c6d-7bff-45cf-b84d-061789257b21" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_WeightedAverageNumberPartnershipUnitsOutstandingDiluted_448061be-d054-4d91-bc96-388b90085cb6" xlink:href="frt-20230630.xsd#frt_WeightedAverageNumberPartnershipUnitsOutstandingDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_frt_WeightedAverageNumberPartnershipUnitsOutstandingDiluted_448061be-d054-4d91-bc96-388b90085cb6" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareReconciliationAbstract_793cc1fb-203e-4d48-9c28-9a5aeb3255e6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareReconciliationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_us-gaap_EarningsPerShareReconciliationAbstract_793cc1fb-203e-4d48-9c28-9a5aeb3255e6" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_frt_EarningsPerCommonShareBasicAndDiluted_d2bf688a-3663-4093-ad14-b25832c34e5b" xlink:href="frt-20230630.xsd#frt_EarningsPerCommonShareBasicAndDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareReconciliationAbstract_793cc1fb-203e-4d48-9c28-9a5aeb3255e6" xlink:to="loc_frt_EarningsPerCommonShareBasicAndDiluted_d2bf688a-3663-4093-ad14-b25832c34e5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerUnitAbstract_3fd6f309-545d-40a7-8e60-f6a6afd2debf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerUnitAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_us-gaap_EarningsPerUnitAbstract_3fd6f309-545d-40a7-8e60-f6a6afd2debf" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted_d20f9a91-e470-4628-890a-5ac1aacd8997" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerUnitAbstract_3fd6f309-545d-40a7-8e60-f6a6afd2debf" xlink:to="loc_us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted_d20f9a91-e470-4628-890a-5ac1aacd8997" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_f227f8cd-47ed-4100-82f4-4b6e699e64b6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_882975ab-e3ec-48a5-ba84-193abfce131d" xlink:to="loc_us-gaap_StatementTable_f227f8cd-47ed-4100-82f4-4b6e699e64b6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_89ada79a-174e-4df9-a3e8-a3e93d7bd625" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_f227f8cd-47ed-4100-82f4-4b6e699e64b6" xlink:to="loc_srt_ConsolidatedEntitiesAxis_89ada79a-174e-4df9-a3e8-a3e93d7bd625" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_89ada79a-174e-4df9-a3e8-a3e93d7bd625_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_89ada79a-174e-4df9-a3e8-a3e93d7bd625" xlink:to="loc_srt_ConsolidatedEntitiesDomain_89ada79a-174e-4df9-a3e8-a3e93d7bd625_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_b3630816-8a94-44ee-918e-0b20f194c24f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_89ada79a-174e-4df9-a3e8-a3e93d7bd625" xlink:to="loc_srt_ConsolidatedEntitiesDomain_b3630816-8a94-44ee-918e-0b20f194c24f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_PartnershipInterestMember_a4947cdd-500b-4c5e-8cc7-12059940f05d" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_PartnershipInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_b3630816-8a94-44ee-918e-0b20f194c24f" xlink:to="loc_srt_PartnershipInterestMember_a4947cdd-500b-4c5e-8cc7-12059940f05d" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
