The cardinal number that is the sum of three and one.

synonyms: 4, four, foursome, IV, Little Joe, quadruplet, quartet, quatern, quaternary, quaternion, tetrad ... show more.

Roget 95: quaternity^†, four, tetrad, quartet, quaternion, square, quarter.    [planar form with four sides] tetract^†, tetragon, quadrangle, rectangle.    [three dimensional object with four surfaces] tetrahedron.    quadrature, quadrifoil, quadriform, quadruplet; quatrefoil.    [object or animal with four legs] tetrapod.    [geographical area with four sides] quadrangle, quad [Coll.].    [electromagnetic object] quadrupole.    [four fundamental studies] quadrivium.    ... show more

Dutch: quaternion, vier, vijf
Polish: czwórka