quaternary period quaternary ammonium compound • quaternate · · · Info · Definitions · Characters · · quaternary period · · Text Common · · Latin · · Scripts 17 · · Length 7 · · Syllables Definitions · · · (noun) last 2 million years. Synonyms: Quaternary, Quaternary period, Age of Man. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 d latin small letter d U+0064 e latin small letter e U+0065 i latin small letter i U+0069 n latin small letter n U+006E o latin small letter o U+006F p latin small letter p U+0070 q latin small letter q U+0071 r latin small letter r U+0072 t latin small letter t U+0074 u latin small letter u U+0075 y latin small letter y U+0079