(1) A set whose members are members of another set; a set contained within another set
WiktionaryText
Noun
With respect to another set, a set such that each of its elements is also an element of the other set.
The set of integers is a subset of the set of reals.
The set {a, b} is a both a subset and a proper subset of {a, b, c} while the set {a, b, c} is a subset of {a, b, c} but not a proper subset of {a, b, c}.
A group of things or people, all of which are in a specified larger group.
We asked a subset of the population of the town for their opinion.
