(UK) A flat triangular piece of plastic or other material, having corners of precise angles, used in technical drawing

(transitive) To release, to free, to give freedom to.

The equipment needed to play chess: a set of chess pieces and a chessboard.

(set theory) A set that is countable.

Alternative spelling of set theoretically

(graph theory) A set of vertices of a graph, such that each vertex in that graph is either in that set or adjacent to a vertex in that set.

(set theory) A mathematical operation that returns a set taking one or more sets as input.

(graph theory) a set of vertices of a graph, such that no pair of them are adjacent to each other; in other words, a set of vertices which are all "independent" of each other

A collection of recordings sold together in a single package.

(mathematics) In a manner which uses set theory / (mathematics) In the sense of set theory