Cluster: Things Grouped Closely Together
A cluster is a group of similar things close together — grapes, stars, houses or cases of a disease. The word is used in statistics, computing and epidemiology.
A cluster is a tight group of similar things. What makes the word useful in science is that it describes a pattern without explaining it: a cluster of cases is a fact to investigate, not yet a cause.
- A close group. *A cluster of houses by the bridge.*
- A group of cases (epidemiology). *A cluster of infections.*
- Linked computers. *A compute cluster.*
- To gather closely (verb). *People clustered around the noticeboard.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | cluster | A star cluster. |
| Verb | cluster | They clustered together. |
| Adjective | clustered | Clustered housing. |
| Noun | clustering | Statistical clustering. |
| Related | bunch | A bunch of keys. |
How it is used in a sentence
- Investigators identified a cluster of cases in one district.Public health usage.
- The Pleiades are an open star cluster.Astronomy — stars formed together and still travelling together.
- Children clustered round the display.The verb, meaning gathered closely.
Clusters across the sciences
- Astronomy — open and globular clusters of stars
- Epidemiology — cases grouped unusually in place or time
- Statistics — cluster analysis, grouping data points by similarity
- Computing — machines linked to work as one system
- Linguistics — a consonant cluster, several consonants in a row
From Old English *clyster*, probably related to *clot*. It is one of the few technical-sounding scientific words in English that is native rather than borrowed from Latin or Greek.
Cluster or bunch?
Bunch is informal and usually means things fastened or held together. Cluster is neutral and works in technical writing.
Does a cluster prove a cause?
No. Clusters occur by chance more often than intuition suggests, which is why investigators test them statistically before drawing conclusions.