# fess up

CEFR B2 · Phrasal verb

Source: https://englishreference.com/word/fess-up
Updated: 2026-04-24

## Definition

to admit that you did something wrong or made a mistake. You use this when you finally tell the truth about something you were hiding.

For teachers: to confess or admit to a fault, error, or minor crime; marked informal register, often used in contexts involving social accountability or lighthearted interrogation.

## Examples

- Come on, fess up—who ate the last cookie?
- After the manager found the broken window, the new employee decided to fess up and apologize.
- Although he initially denied any involvement in the prank, he eventually had to fess up when the security footage was reviewed.

## Pitfalls

- Not "He fessed up his mistake." but "He fessed up to his mistake." — when mentioning the specific mistake, the preposition 'to' is required after the phrase.

## Usage notes

- often used as an imperative or followed by the preposition 'to' and a noun or gerund.
- Teaching tip: explain that 'fess' is a clipped form of 'confess'; highlight its informal nature compared to 'admit' or 'confess' to help students with register awareness.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.