mid-14c., "deliverance from sin," from Old French redemcion (12c.) and directly from Latin redemptionem (nominative redemptio) "a buying back, releasing, ransoming" (also "bribery"), noun of action from past participle stem of redimere "to redeem, buy back," from red- "back" (see re-) + emere "to take, buy, gain, procure" (see exempt). The -d- is from the Old Latin habit of using red- as the form of re- before vowels. In the Mercian hymns, Latin redemptionem is glossed by Old English alesnisse.