1.Definition: four people considered as a unit

"He joined a barbershop quartet", "The foursome teed off before 9 a.m."

Related Noun(s):quartet, quartette

Category: General

2.Definition: the cardinal number that is the sum of three and one

Related Noun(s):four, iv, quadruplet, quartet, quatern, quaternary, quaternion, quaternity, tetrad

Category: General