Confess
late Middle English: from Old French confesser, from Latin confessus, past participle of confiteri ‘acknowledge’, from con- (expressing intensive force) + fateri ‘declare, avow’.
wiktionary
From Middle English confessen, from Anglo-Norman confesser, from Old French confesser, from Medieval Latin confessō(“I confess”), a derivative of Latin confessus (Old French confés), past participle of cōnfiteor(“I confess, I admit”) from con- + fateor(“I admit”). Displaced Middle English andetten(“to confess, admit”) (from Old English andettan).
etymonline
confess (v.)
late 14c., transitive and intransitive, "make avowal or admission of" (a fault, crime, sin, debt, etc.), from Old French confesser (transitive and intransitive), from Vulgar Latin *confessare, a frequentative form from Latin confess-, past participle stem of confiteri "to acknowledge," from assimilated form of com "together" (see con-) + fateri "to admit," akin to fari "speak," from PIE root *bha- (2) "to speak, tell, say."
Its original religious sense was in reference to one who avows his religion in spite of persecution or danger but does not suffer martyrdom (compare confessor). Old French confesser thus had also a figurative sense of "to harm, hurt, make suffer." Related: Confessed; confessing. An Old English word for it was andettan.
