confessyoudaoicibaDictYouDict[confess 词源字典]
confess: [14] Confess comes from Latin confitērī ‘acknowledge’. This was a compound verb formed from the intensive prefix com- and fatērī ‘admit’ (a relative of English fable, fame, and fate). Its past participle was confessus, and this was taken as the basis of a new Vulgar Latin verb *confessāre, which passed into English via Old French confesser.
=> fable, fame, fate[confess etymology, confess origin, 英语词源]
confess (v.)youdaoicibaDictYouDict
late 14c., from Old French confesser (transitive and intransitive), from Vulgar Latin *confessare, from Latin confess-, past participle stem of confiteri "to acknowledge," from com- "together" (see com-) + fateri "to admit," akin to fari "speak," from PIE root *bha- (2) "to speak, tell, say" (see fame (n.)).

Its original religious sense was of one who avows his religion in spite of persecution or danger but does not suffer martyrdom. Old French confesser thus had a figurative sense of "to harm, hurt, make suffer." Related: Confessed; confessing. An Old English word for it was andettan.