relation (n.)youdaoicibaDictYouDict[relation 词源字典]
late 14c., "connection, correspondence;" also "act of telling," from Anglo-French relacioun, Old French relacion "report, connection" (14c.), from Latin relationem (nominative relatio) "a bringing back, restoring; a report, proposition," from relatus (see relate). Meaning "person related by blood or marriage" first attested c. 1500. Stand-alone phrase no relation "not in the same family" is attested by 1930.[relation etymology, relation origin, 英语词源]