1. (noun)
four, 4, IV, tetrad, quatern, quaternion, quaternary, quaternity, quartet, quadruplet, foursome, Little Joe
- the cardinal number that is the sum of three and one Synonyms: quartette, quadruple, quaternion, quartet, quaternary, quad, tetrad, four, foursome, quaternity, intravenous feeding, quadruplet, quatern, four-spot