subset

subset — noun

1. a group made up of members that are all contained within a bigger group of the s

1.nounB2
Definition

a group made up of members that are all contained within a bigger group of the same kind

Example

Eleni's research team studied a subset of 200 patients from the larger hospital database.

collocation: subset of + number + noun

Only a small subset of the museum's collection was displayed during the renovation.

Common collocations
  • subset of [group]
  • small subset
  • large subset
  • proper subset
  • finite subset
  • subset of patients
  • subset of data
  • subset of users
Synonyms
  • part

    much more general; does not carry the idea that every member belongs to the larger set

  • portion

    focuses on a share or section of a whole rather than group membership

  • subgroup

    used especially for people or social groups rather than data or objects

Antonyms
  • superset

    the larger set that fully contains the subset; used mainly in mathematics

Grammar Patterns

subset + of + noun phrase

Usage Note

Subset is used both in mathematics and in everyday language. In non-technical contexts it simply refers to a part of a larger group, but it always implies that every member of the smaller group is also a member of the larger group.

Common Mistakes

Red apples are a subset of apples that are sweet.
Sweet red apples are a subset of apples.
A subset only describes membership in a larger group; it should not add conditions that not all members of the subset actually share.

Word family

  • subsets
    noun (plural)B2

Synonym discussion

Sense: noun/1

Subset, part, portion, and subgroup all refer to something that belongs to a larger whole, but they differ in precision. Subset is the most exact term: it requires that every member of the smaller group also be a member of the larger group — no exceptions. Part is the broadest and most common word; it can refer to any piece or section of a whole without implying membership rules (a part of a cake, a part of a story). Portion emphasizes the amount or share, often measured or divided (a portion of the budget, a portion of food). Subgroup is used mostly for people or identifiable categories within a larger social or organizational group (a subgroup of students, a demographic subgroup). For everyday writing, part works well; for precise technical or data-driven contexts, subset is the better choice.

subset ↗part ↗portion ↗subgroup

Common collocations

Nouns

  • subset of patients
  • subset of data
  • subset of people
  • subset of cases
  • subset of users
  • subset of responses

Phrases

  • a subset of
  • a small subset of
  • a large subset of
  • a proper subset of

Prepositions

Etymology

LatinEnglish

Subset is formed by combining the prefix sub- (from Latin, meaning 'under' or 'below') with set (a word that took on the meaning 'a collection of items' in mathematics during the 19th century). The term became widely used in the mid-1900s as set theory entered school mathematics curricula around the world.