clump

American  

[kluhmp] / klʌmp /

noun

1. a small, close group or cluster, especially of trees or other plants.

2. a lump or mass

3. a heavy, thumping step, sound, etc.

4. Immunology. a cluster of agglutinated bacteria, red blood cells, etc.

5. a thick extra sole on a shoe.

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verb (used without object)

1. Also clomp to walk heavily and clumsily.

2. Immunology. to gather or be gathered into clumps; agglutinate.

verb (used with object)

1. to gather or form into a clump; mass.

clump British  

/ klʌmp /

noun

1. a cluster, as of trees or plants

2. a dull heavy tread or any similar sound

3. an irregular mass

   a clump of hair or earth

4. an inactive mass of microorganisms, esp a mass of bacteria produced as a result of agglutination

5. an extra sole on a shoe

6. slang a blow

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verb

1. (intr) to walk or tread heavily

2. to gather or be gathered into clumps, clusters, clots, etc

3. to cause (bacteria, blood cells, etc) to collect together or (of bacteria, etc) to collect together

4. slang (tr) to punch (someone)

Other Word Forms

• clumpiness
  noun
• clumpish
  adjective
• clumplike
  adjective
• clumpy
  adjective

Etymology

Origin of clump

First recorded in 1580–90; akin to Dutch klompe “lump, mass,” Old English clympre “lump of metal”

Explanation

A clump is a "bunch" or a "cluster." If you're a gardener, the last thing you want to see is a clump of weeds growing in the middle of your newly groomed lawn. Essentially, a clump is a grouping. You might see a clump of sheep grazing in a field or you might throw a clump of clothes into the washing machine. Clump can also mean lump, like when you find a clump of grass stuck to your shoe. As a verb, clump means "to gather," as in "a flock of birds clumped together in a tree."

Example Sentences

Normal tau supports brain health, but the protein can clump into tangles that damage brain cells and cause memory loss.

From Barron's • May 14, 2026

Whether the incoming object was a solid rock like the marble or a looser clump of dust, the boulders on the asteroid's surface shaped the incoming material into the distinctive fan patterns.

From Science Daily • Mar. 8, 2026

"The required plasma clump is consistent with CMEs launched by the Sun and other stars in the Milky Way."

From Science Daily • Jan. 28, 2026

Make sure to stir the rice and milk so that the rice doesn’t clump up.

From Salon • Jan. 10, 2026

A new clump of weeds had mysteriously sprouted in the yard.

From "The Wild Robot Escapes" by Peter Brown

Related Words

• blob
• bundle
• chunk
• cluster
• hunk
• jumble
• knot
• lump
• wad