cluster

American  

[kluhs-ter] / ˈklʌs tər /

noun

1. a number of things of the same kind, growing or held together; a bunch.

   a cluster of grapes.

2. a group of things or persons close together.

   There was a cluster of tourists at the gate.

3. U.S. Army. a small metal design placed on a ribbon representing an awarded medal to indicate that the same medal has been awarded again.

   oak-leaf cluster.

4. Phonetics. a succession of two or more contiguous consonants in an utterance, as the str- cluster of strap.

5. Astronomy. a group of neighboring stars, held together by mutual gravitation, that have essentially the same age and composition and thus supposedly a common origin.

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verb (used with object)

1. to gather into a cluster or clusters.

2. to furnish or cover with clusters.

verb (used without object)

1. to form a cluster or clusters.

   The people clustered around to watch.

   Synonyms:

   bunch, crowd, throng, gather, group

cluster British  

/ ˈklʌstə /

noun

1. a number of things growing, fastened, or occurring close together

2. a number of persons or things grouped together

3. military a metal insignia worn on a medal ribbon to indicate a second award or a higher class of a decoration or order

4. military

   1. a group of bombs dropped in one stick, esp fragmentation and incendiary bombs

   2. the basic unit of mines used in laying a minefield

5. astronomy an aggregation of stars or galaxies moving together through space

6. a group of two or more consecutive vowels or consonants

7. statistics a naturally occurring subgroup of a population used in stratified sampling

8. chem

   1. a chemical compound or molecule containing groups of metal atoms joined by metal-to-metal bonds

   2. the group of linked metal atoms present

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verb

1. to gather or be gathered in clusters

Other Word Forms

• clustered
  adjective
• clusteringly
  adverb
• clustery
  adjective
• intercluster
  adjective
• subcluster
  noun
• unclustered
  adjective
• unclustering
  adjective

Etymology

Origin of cluster

before 900; Middle English; Old English cluster, clyster bunch; cognate with Low German kluster

Explanation

A cluster is a small group of people or things. When you and your friends huddle awkwardly around the snack table at a party, whispering and trying to muster enough nerve to hit the dance floor, you’ve formed a cluster. Cluster comes to us from the Old English word clyster, meaning bunch. Nowadays, you can use cluster as either a noun or a verb. When we were kids, we would stand in a cluster (noun) on the street corner, eagerly awaiting the appearance of the Good Humor truck every afternoon. Then we would cluster (verb) eagerly around the driver, demanding ice cream. Virtually anything can form a cluster — flowers, cells, stars, human beings, and even events.

Example Sentences

Private-school critics argue that when you cluster the high-performing students in one school and the struggling ones in another, the overall national average suffers.

From The Wall Street Journal • May 12, 2026

The first laser beam established the position of each cluster with an accuracy of about 10 nm and placed the particles into a quantum superposition, meaning they could follow multiple paths through the apparatus simultaneously.

From Science Daily • May 11, 2026

In the current cluster, the type of hantavirus involved is called the Andes virus, found in South America.

From Barron's • May 7, 2026

A cluster of cases 13 years ago was one of the first major signs that something was amiss.

From Salon • May 7, 2026

“Ar-ki-pe-la-go. An old word, for a cluster of islands.”

From "Impossible Creatures" by Katherine Rundell

Related Words

• array
• assemblage
• band
• batch
• bunch
• bundle
• chunk
• clump
• collection
• knot