1 B2 neutral
Of physical matter: to stick together and form a dense lump or mass.
"The mascara had clumped up because she forgot to close the tube properly."
inseparable
clump up
B2 neutral inseparable transitive/intransitive
To form or gather into a dense mass or clump; or to cause things to stick together into lumps.
In plain English
When things stick together and form a big group or lump instead of staying separate.
What does "clump up" mean?
2 meanings, ordered from most common to least. Color-coded by CEFR level.
2 B2 informal
Of people or animals: to gather into a tight group or cluster.
"The tourists clumped up at the entrance, blocking the doorway for everyone else."
inseparable
Literal vs figurative
Words literally mean
To form ('up') into a clump ('clump').
Actually means
When things stick together and form a big group or lump instead of staying separate.
Usage tip
Used in both physical contexts (soil, hair, powder) and biological or social contexts (cells, animals, people). The 'up' particle suggests completeness — becoming one solid mass. Common in scientific and everyday contexts.
Words that pair with "clump up"
Natural word combinations native speakers use most often.
hair soil cells crowd powder particles
How to conjugate "clump up"
The five tense forms you'll use most often.
Base
clump up
I/you/we/they
3rd person
clumps up
he/she/it
Past simple
clumped up
yesterday
Past participle
clumped up
have + pp
-ing form
clumping up
continuous
Hear "clump up" in the wild
Listen to native speakers using "clump up" in real YouTube videos — click a clip to watch it on Looplines.
Keep exploring
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