# cock up

CEFR C1 · Phrasal verb

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

## Definition

to do something very badly or make a big mistake. You use this when you fail at a task because of poor planning or a silly error.

For teachers: to ruin or bungle a task through incompetence or carelessness; a transitive or intransitive phrasal verb used in British English with a highly informal, slightly vulgar register.

## Examples

- I really cocked up that presentation today.
- The organizers completely cocked up the seating arrangements, so half the guests had nowhere to sit.
- Despite months of meticulous preparation, the logistics team managed to cock up the entire operation within the first hour of the launch.

## Pitfalls

- Not "He cocked it out." but "He cocked it up." — the particle must be 'up'; 'cock up' is a fixed phrasal verb meaning to bungle.

## Usage notes

- primarily British English and very informal; it can be used with or without an object.
- Teaching tip: advise students that while common in the UK, it is borderline slang and may be considered mildly offensive or unprofessional in formal business settings.

---

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.