early 14c., "performance of an act set forth by a priest or other Church authority to atone for sin," from Old French satisfaction (12c.), from Latin satisfactionem (nominative satisfactio) "a satisfying of a creditor," noun of action from past participle stem of satisfacere (see satisfy). Senses of "contentment, appeasement" and "action of gratifying" first recorded late 14c.; the former not common before 16c.[satisfaction etymology, satisfaction origin, 英语词源]