definition of
[quartet]

[1] #1 quartet n. [four, 4, IV, tetrad, quatern, quaternion, quaternary, quaternity, quadruplet, foursome, Little Joe] the cardinal number that is the sum of three and one. wn

[2] #2 quartet n. [quartette] four performers or singers who perform together. wn

[3] #3 quartet n. [quartette, quadruplet, quadruple] a set of four similar things considered as a unit. wn

[4] #4 quartet n. [quartette, foursome] four people considered as a unit; "he joined a barbershop quartet"; "the foursome teed off before 9 a.m.". wn

[5] #5 quartet n. [quartette] a musical composition for four performers. wn