muck up: meaning, definition, pronunciation and examples

High (informal)
UK/ˈmʌk ʌp/US/ˈmʌk ʌp/

Informal

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Quick answer

What does “muck up” mean?

To make a mess of something.

Audio

Pronunciation

Definition

Meaning and Definition

To make a mess of something; to spoil, ruin, or perform poorly.

To cause confusion or disorder; to behave irresponsibly, especially in a way that damages one's own or others' plans or opportunities.

Dialectal Variation

British vs American Usage

Differences

More common in British and Australian English; American English uses 'mess up', 'screw up', or 'foul up' more frequently. The noun 'muck' (dirt) is less common in AmE.

Connotations

In BrE, it can sound colloquial but not overly harsh. In AmE, it might be perceived as a Britishism or sound slightly quaint.

Frequency

High frequency in BrE informal speech; medium-low in AmE, where synonyms are preferred.

Grammar

How to Use “muck up” in a Sentence

muck up + noun phrase (transitive)muck up + reflexive pronoun

Vocabulary

Collocations

strong
completely muck uptotally muck upreally muck up
medium
muck up the plansmuck up the interviewmuck up my chances
weak
muck up the roommuck up the projectmuck up everything

Examples

Examples of “muck up” in a Sentence

verb

British English

  • I hope I don't muck up my driving test.
  • The bad weather has mucked up our picnic plans.
  • He's always mucking things up.

American English

  • I totally mucked up the presentation. (used knowingly as BrE)
  • Don't muck up this opportunity.
  • The software update mucked up my settings.

adverb

British English

  • (Not used as an adverb.)

American English

  • (Not used as an adverb.)

adjective

British English

  • (Not typically used as adjective. Past participle 'mucked-up' is rare.)

American English

  • (Not typically used as adjective.)

Usage

Meaning in Context

Business

Avoid in formal reports; used informally to mean 'cause a project failure'.

Academic

Highly unlikely in formal writing; possible in casual student conversation about exams.

Everyday

Very common in informal BrE conversation for mistakes and failures.

Technical

Not used.

Vocabulary

Synonyms of “muck up”

Vocabulary

Antonyms of “muck up”

Watch out

Common Mistakes When Using “muck up”

  • Incorrect: 'I mucked up the room' (if you mean you cleaned it).
  • Incorrect: 'Don't muck up!' (without an object – needs 'it').

FAQ

Frequently Asked Questions

No, it is informal but not swearing. It is milder than 'screw up' or 'fuck up'.

No, that is a common confusion. 'Muck out' means to clean (e.g., a stable). 'Muck up' only means to spoil or dirty.

Yes, it is a separable phrasal verb. 'Don't muck up the plan' and 'Don't muck the plan up' are both correct, though the first is more common.

They are largely synonymous. 'Muck up' is more British, 'mess up' is universal but more American. 'Mess up' can also mean to make a place untidy more readily than 'muck up'.

To make a mess of something.

Muck up is usually informal in register.

Muck up: in British English it is pronounced /ˈmʌk ʌp/, and in American English it is pronounced /ˈmʌk ʌp/. Tap the audio buttons above to hear it.

Phrases

Idioms & Phrases

  • muck up the works
  • muck it up

Learning

Memory Aids

Mnemonic

Imagine a farmer stepping in MUCK (manure) and then UP-setting a bucket, ruining his clean boots – he MUCKED UP.

Conceptual Metaphor

FAILURE IS MAKING SOMETHING DIRTY / DISORDER IS DIRT

Practice

Quiz

Fill in the gap
I had one job to do, and I managed to it up completely.
Multiple Choice

In which context is 'muck up' LEAST appropriate?

Practise

Train, don’t just look up

Five interactive tools to remember words, train your ear, and build vocabulary in real context — drawn from this dictionary.

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