duff

duff — adjective

1. of very poor quality or not working correctly — for example, a duff mobile phone

1.adjectiveB2
Definition

of very poor quality or not working correctly — for example, a duff mobile phone that freezes every few minutes, or a duff performance that the audience walks out of.

Example

Jiwoo's new phone was duff and kept switching off for no reason.

be + duff for defective items

The battery in Mert's torch was duff and ran out after just one hour.

Common collocations
  • completely duff
  • absolutely duff
  • duff battery
  • duff phone
  • duff equipment
Synonyms
  • rubbish

    same informal British register, slightly broader in use

  • lousy

    more widely understood across dialects, can describe experiences too

  • faulty

    neutral and more specific — suggests a technical defect rather than general poor quality

Antonyms

Grammar Patterns

be + duff

duff + noun

Usage Note

This sense is almost exclusively British informal. 'Duff' is more common in speech than in writing and is not used in formal or academic contexts.

Common Mistakes

This is a duff idea.
This is a bad idea.
'duff' is not typically used for abstract concepts like ideas; it mainly describes concrete objects that are faulty or of poor quality.
The meeting was duff.
The meeting was terrible.
'duff' sounds unnatural for events or situations; use 'bad' or 'terrible' instead.

duff — noun

duff — verb

Word family

  • duffer
    nounC1

Synonym discussion

Sense: adjective/1

Duff, rubbish, lousy, and faulty are all words for something of poor quality, but they differ in tone, scope, and dialect. Duff is primarily British slang for a concrete thing that does not work properly, such as a duff kettle or a duff phone — it is rarely used for abstract concepts like ideas or experiences. Rubbish is also British informal but broader: a film, a meal, or a piece of work can all be rubbish. Lousy is more widely understood across dialects and can describe objects, experiences, and treatment (a lousy day, lousy service). Faulty is the most neutral and formal of the four — it suggests a specific technical defect rather than general worthlessness. For example: 'The toaster was faulty and caught fire' describes a precise fault, whereas 'The toaster was duff, so I threw it away' implies it was simply no good.

duff ↗rubbish ↗lousyfaulty

Common collocations

Adverbs

Phrases

  • get off your duff
  • up the duff

Prepositions

Etymology

Northern English / ScotsEnglish

The word 'duff' started life as a northern British pronunciation of 'dough' — the raw mixture for bread. In the 1800s, 'duff' came to mean a heavy boiled pudding (plum duff). Because this pudding was dense and unexciting, the word shifted to mean anything of poor quality. The noun meaning 'buttocks' comes from the same source: something soft and lumpy. The phrase 'get off your duff' (stop being lazy) grew out of the buttocks meaning. 'Up the duff' (pregnant) may use the same pudding metaphor — like 'a bun in the oven.' The verb sense (stealing livestock by rebranding) has a separate history and is thought to come from thieves' slang where 'duff' meant to disguise or fake something.