tetrad tetracyclic • tetradactyl · · · Info · Definitions · Synonyms · Characters · · tetrad · · Text Latin · · Script 6 · · Length Definitions · · · (noun) the cardinal number that is the sum of three and one. Synonyms: four, 4, IV, quatern, quaternion, quaternary, quaternity, quartet, quadruplet, foursome, Little Joe. · · Noun Definition 1 Synonyms · · · four · · Synonym 1 4 · · Synonym 2 iv · · Synonym 3 quatern · · Synonym 4 quaternion · · Synonym 5 quaternary · · Synonym 6 quaternity · · Synonym 7 quartet · · Synonym 8 quadruplet · · Synonym 9 foursome · · Synonym 10 little joe · · Synonym 11 Characters · · a latin small letter a U+0061 d latin small letter d U+0064 e latin small letter e U+0065 r latin small letter r U+0072 t latin small letter t U+0074