# gum up

CEFR B2 · Phrasal verb

Source: https://englishreference.com/word/gum-up
Updated: 2026-10-22

## Definition

to stop something from working smoothly or correctly. You use this when something gets stuck or blocked, like a machine or a process.

For teachers: to cause a mechanism or process to malfunction or cease operating efficiently by clogging or obstructing it. Transitive; often used figuratively in the fixed expression 'gum up the works'.

## Examples

- Don't put sticky tape there; it will gum up the printer.
- The heavy snow began to gum up the city's transport system, causing massive delays for commuters.
- The bureaucratic inertia within the department threatened to gum up the entire legislative agenda before the summer recess.

## Pitfalls

- Not "The dirt will gum the engine." but "The dirt will gum up the engine." — The particle 'up' is necessary to convey the meaning of clogging or stopping the mechanism.

## Usage notes

- This is a transitive phrasal verb that usually takes a physical object or an abstract system as its object.
- Teaching tip: Introduce this alongside the idiom 'gum up the works' to show how a physical metaphor describes a failing system.

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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.