proterozoic eon proterozoic aeon • protervity · · · Info · Definitions · Characters · · proterozoic eon · · Text Common · · Latin · · Scripts 15 · · Length 7 · · Syllables Definitions · · · (noun) from 2,500 to 544 million years ago; bacteria and fungi; primitive multicellular organisms. Synonyms: Proterozoic, Proterozoic eon, Proterozoic aeon. · · Noun Definition 1 Characters · · space U+0020 c latin small letter c U+0063 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 r latin small letter r U+0072 t latin small letter t U+0074 z latin small letter z U+007A