fess
UK[fɛs]US[fɛs]
v
To confess or admit something, especially in the phrase "to fess up".
Etymology
The word 'fess' is a 19th-century American colloquial shortening of the verb 'confess'. 'Confess' itself entered English from Old French 'confesser', which derived from Latin 'confessus', the past participle of 'confiteri' meaning 'to acknowledge, admit'. The Latin root is a compound of 'con-' (an intensive prefix meaning 'altogether') and 'fateri' (to admit). The clipped form 'fess', almost exclusively used in the phrasal verb 'fess up', retains the core semantic notion of admission but carries a more informal, conversational tone.
Analysis
This word is a simplex, clipped form of the longer word "confess". It is not productively built from smaller, independent morphemes in modern English.
Examples
You'd better fess up about who broke the window.
After some questioning, he finally fessed to taking the last cookie.
Come on, fess up—it was your idea, wasn't it?