1 B2 neutral
To cause a mechanical device to stop working by blocking or clogging it with a sticky substance.
"The old oil had dried out and completely gummed up the engine's moving parts."
separable
gum up
B2 informal separable transitive
To cause a mechanism, plan, or process to stop working properly by clogging it or making it inefficient.
In plain English
To block or mess up a machine or plan so that it can't work properly — like when sticky stuff gets into a machine.
What does "gum up" mean?
2 meanings, ordered from most common to least. Color-coded by CEFR level.
2 B2 idiomatic informal
To disrupt or obstruct a process, plan, or system so that it cannot function efficiently.
"The new regulation has completely gummed up the approval process — it's taking weeks longer than it should."
separable
Literal vs figurative
Words literally mean
To fill something with gum (sticky substance) so it seizes up and stops working.
Actually means
To block or mess up a machine or plan so that it can't work properly — like when sticky stuff gets into a machine.
Usage tip
Common in both literal (mechanical) and figurative (organizational or procedural) senses. The expression 'gum up the works' is an established idiom meaning to disrupt a process. Used in informal everyday speech and journalism.
Words that pair with "gum up"
Natural word combinations native speakers use most often.
works machine system engine process plans
How to conjugate "gum up"
The five tense forms you'll use most often.
Base
gum up
I/you/we/they
3rd person
gums up
he/she/it
Past simple
gumed up
yesterday
Past participle
gumed up
have + pp
-ing form
guming up
continuous
Hear "gum up" in the wild
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Other ways to say "gum up"
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