- An informal command or strong encouragement for someone to confess or admit to something they have done wrong or kept secret.
Explanation
Origin
- Likely a colloquial shortening and alteration of the verb confess.
- The exact evolution is uncertain, but it may have been influenced by professor (in the sense of professing or declaring something).
- Emerged in American English slang around the mid-20th century.
- The particle 'up' adds emphasis, similar to its use in 'own up,' 'speak up,' or 'pony up,' suggesting bringing something out into the open.
Synonyms & Related Expressions
Alternatives
Slang/Informal:
- Spit it out (Tell me now)
- Own up
- Cough it up (Often refers to money or information, but can imply confession)
- Level with me (Be honest with me)
Vulgar/Emphatic (Demanding confession forcefully):
- Tell me the fucking truth now!
- Stop bullshitting and fess up! / Stop bullshitting and own up!
Milder/Formal:
- Please admit it. / Would you please admit it?
- We need you to tell the truth.
- It would be best if you confessed.
- Please be honest.
Situational Appropriateness
- Informal.
- Suitable among friends, family (especially when talking to children), or peers in casual situations.
- Can sound accusatory, demanding, or even childish in formal or professional settings. Generally inappropriate to say to a superior, unless the context is exceptionally informal or playful.
Misunderstanding Warnings
- Generally clear in meaning.
- Non-native speakers should primarily note its informality and the context of admitting wrongdoing. It's not a neutral request for information.
Examples
- Okay, who ate the last piece of cake? Fess up!
- Come on, fess up. I know you borrowed my sweater without asking.
- The police told the suspect it was time to fess up.
Dialogue
Parent: Someone tracked mud all over the clean kitchen floor right after I mopped it. Fess up, which one of you was it?
Child 1: (Shakes head) Wasn't me! I took my shoes off.
Child 2: (Looking down at feet) Uh... maybe... maybe it was me. Sorry, Mom. I forgot.
Parent: Thank you for fessing up. Now, please go get the mop and clean it.
Social Media Examples
- Playful Post: Alright, who finished the coffee and didn't make a new pot this morning? Fess up! 😉 #OfficeLife #CoffeeAddict
- Forum Thread: Someone keeps downvoting all my posts for no reason. If it's you, just fess up, it's anonymous anyway.
Response Patterns
The accused person might:
- Confess: Okay, okay, it was me. I did it.
- Deny: It wasn't me! / I have no idea what you're talking about.
- Deflect/Blame shift: Why are you looking at me? / Maybe Tim did it.
- Remain silent.
Common Follow-up Questions/Actions
- If someone 'fesses up,' the conversation typically moves to discussing the consequences, motivations, or making amends (Okay, since you fessed up, just promise not to do it again.).
- If they deny, the accuser might press further (Are you sure?), present evidence, or drop the subject.
Conversation Starter
- No. Used specifically when suspecting someone of wrongdoing and urging them to admit it.
Intonation
- Can range from playful and teasing to demanding and serious.
- Stress usually falls firmly on Fess: FESS up.
- Often has a rising intonation if gently urging someone (Come on, fess up?), or a falling, more command-like intonation if demanding (Fess up! Now!).
Generation Differences
- Understood by most generations.
- Feels perhaps slightly more common in the speech of older generations (Gen X, Boomers) or when adults address children. Younger generations might be more likely to use Come clean or just directly ask Did you do this?.
Regional Variations
- Primarily American English in origin and common usage.
- Understood in other regions, but Own up might be a more frequent equivalent in British English.