(mathematical analysis) A set which is equal to its set of limit points. That is, a set A is perfect if A'=A.

plural of set piece

(intransitive, idiomatic) To begin working. / (intransitive, idiomatic, with gerund) To begin working at. / (transitive) To cause to begin working.

(music) A wind instrument incorporating multiple pipes, such as a panpipe or bagpipe. / (idiomatic) Voice for singing.

plural of set phrase

plural of set square

(intransitive, followed by to) To light using fire; to cause to be on fire; to set alight.

(idiomatic) To trigger movement or progress; to get going.

(mathematics) The set of all the edges of a graph

A collection of drums and other percussion instruments designed to be played together.