confessyoudaoicibaDictYouDict
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
professyoudaoicibaDictYouDict
profess: [14] Profess comes from prōfessus, the past participle of Latin prōfitērī ‘declare publicly’. This was a compound verb formed from the prefix prō- ‘forth, in public’ and fatērī ‘acknowledge, confess’ (a relative of English fable, fame, and fate and source also of confess). A professor [14] is etymologically someone who ‘makes a public claim’ to knowledge in a particular field; and someone’s profession [13] is the area of activity in which they ‘profess’ a skill or competence.
=> confess, fable, fame, fate
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.
profess (v.)youdaoicibaDictYouDict
early 14c., "to take a vow" (in a religious order), a back-formation from profession or else from Old French profes, from Medieval Latin professus "avowed," literally "having declared publicly," past participle of Latin profiteri "declare openly, testify voluntarily, acknowledge, make public statement of," from pro- "forth" (see pro-) + fateri (past participle fassus) "acknowledge, confess," akin to fari "to speak," from PIE root *bha- (2) "to speak, tell, say" (see fame (n.)). Meaning "declare openly" first recorded 1520s, "a direct borrowing of the sense from Latin" [Barnhart]. Related: Professed; professing.