definition of
[quadruplet]

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

[2] #2 quadruplet n. [quad] one of four children born at the same time from the same pregnancy. wn

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