Are yams and sweet potatoes the same?
early 14c., "to come back, come or go back to a former position" (intransitive), from Old French retorner "turn back, turn round, return" (Modern French retourner), from re- "back" (see re-) + torner "to turn" (see turn (v.)). Transitive sense of "report officially" is early 15c.; "to send back" is mid-15c.; that of "to turn back" is from c.1500. Meaning "to give in repayment" is 1590s; that of "give back, restore" c.1600. Related: Returned; returning.
late 14c., "act of coming back," also "official report of election results," from Anglo-French retorn, Old French retorne, verbal noun from retorner (see return (v.)). In ball games from 1833; specifically in tennis from 1886. Meaning "a yield, a profit" is recorded from 1620s. Meaning "a thing sent back" is from 1875. Many happy returns of the day was used by Addison (1716). Mailing return address attested from 1884.