1.Definition: a set of four similar things considered as a unit

Related Noun(s):quadruple, quartet, quartette

Category: General

2.Definition: one of four children born at the same time from the same pregnancy

Related Noun(s):quad

Category: People

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

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

Category: General