late 14c., "action of confessing," originally in religion, from Old French confession (10c.), from Latin confessionem (nominative confessio) "confession, acknowledgement," noun of action from past participle stem of confiteri (see confess). In law, from 1570s. Meaning "that which is confessed" is mid-15c. An Old English word for it was andettung, also scriftspræc.