relation Look up relation at Dictionary.com
1390, from Anglo-Fr. relacioun, O.Fr. relacion (14c.), from L. relationem (nom. relatio) "a bringing back, restoring," from relatus (see relate). Meaning "person related by blood or marriage" first attested 1502. Relationship "sense of being related" is from 1744; meaning "an affair, a romantic or sexual relationship" is attested from 1944. Stand-alone phrase no relation "not in the same family" is attested by 1930.