Set2  n. 1 group of linked or similar things or persons. 2 section of society. 3 collection of objects for a specified purpose (cricket set; teaset). 4 radio or television receiver. 5 (in tennis etc.) Group of games counting as a unit towards winning a match. 6 math. Collection of things sharing a property. 7 direction or position in which something sets or is set. 8 slip, shoot, bulb, etc., for planting.