cluster

1 of 2

noun

clus·​ter ˈklə-stər 

: a number of similar things that occur together: such as

a

: two or more consecutive consonants or vowels in a segment of speech

b

: a group of buildings and especially houses built close together on a sizable tract in order to preserve open spaces larger than the individual yard for common recreation

c

: an aggregation of stars or galaxies that appear close together in the sky and are gravitationally associated

the Perseus cluster of galaxies

d

: a larger than expected number of cases of disease (such as leukemia) occurring in a particular locality, group of people, or period of time

e

: a number of computers networked together in order to function as a single computing system

Consisting of groups of inexpensive machines cobbled together, clusters in many ways have supplanted traditional supercomputers.

—Elizabeth K. Wilson

clustery

ˈklə-st(ə-)rē 

adjective

cluster

2 of 2

verb

clustered; clustering ˈklə-st(ə-)riŋ 

transitive verb

1

: to collect into a cluster

cluster the tents together

2

: to furnish with clusters

The bridge was clustered with men and officers …

—Herman Wouk

intransitive verb

: to grow, assemble, or occur in a cluster

they clustered around the fire

Synonyms of cluster

Noun

• batch
• array
• collection
• constellation
• bunch
• grouping
• group
• assemblage
• set
• clump
• package
• battery
• lot

Verb

• gather
• converge
• rendezvous
• meet
• assemble
• conglomerate
• convene
• congregate
• get together

Examples of cluster in a Sentence

Noun

a cluster of cottages along the shore

A small cluster of people had gathered at the scene of the accident.

Verb

The children clustered around the storyteller.

the mice clustered together into a small burrow

Recent Examples on the Web

Noun

Decades of toxic air The staggering impacts begin during the extraction of fossil fuels for oil refineries and chemical plants, including a cluster in and around Sarnia, Ontario, at the southern tip of Lake Huron. — Michael Hawthorne, Chicago Tribune, 23 Aug. 2026

There's no public benchmark for what a whole cluster fetches when the seller has no choice. — Robert J. Szczerba, Forbes.com, 23 Aug. 2026

Verb

Most of the large developments with urban vibes in Sandy Springs are clustered around the Perimeter rather than the city’s northern edge. — Zachary Hansen, AJC.com, 19 Aug. 2026

Sacramento was crawling Saturday as crowds packed Bugtopia, winding between tables and clustering around displays with the restless motion of a human-sized ant colony. — Naomi Taxay, Sacbee.com, 15 Aug. 2026

Word History

Etymology

Noun and Verb

Middle English, from Old English clyster; akin to Old English clott clot

First Known Use

Noun

before the 12th century, in the meaning defined above

Verb

14th century, in the meaning defined at transitive sense 1

Phrases Containing cluster

• cluster analysis
• cluster bomb
• cluster headache
• globular cluster
• inter-cluster
• oak-leaf cluster
• sub-cluster

Rhymes for cluster

• bluster
• buster
• duster
• juster
• luster
• lustre
• maister
• muster
• thruster
• trustor
• adjuster
• baluster

Kids Definition

cluster

1 of 2 noun

clus·​ter ˈkləs-tər 

: a number of similar things growing, collected, or grouped together : bunch

a cluster of houses

a flower cluster

cluster

2 of 2 verb

clustered; clustering -t(ə-)riŋ 

: to grow, collect, or gather in a cluster

Medical Definition

cluster

noun

clus·​ter ˈkləs-tər 

: a larger than expected number of cases of disease (as leukemia) occurring in a particular locality, group of people, or period of time