geological period geologically • geological phenomenon · · · Info · Definitions · Synonyms · Characters · · geological period · · Text Common · · Latin · · Scripts 17 · · Length 7 · · Syllables Definitions · · · (noun) a unit of geological time during which a system of rocks formed. Synonyms: period, geological period. Example: "Ganoid fishes swarmed during the earlier geological periods." · · Noun Definition 1 Synonyms · · · period · · Synonym 1 Characters · · space U+0020 a latin small letter a U+0061 c latin small letter c U+0063 d latin small letter d U+0064 e latin small letter e U+0065 g latin small letter g U+0067 i latin small letter i U+0069 l latin small letter l U+006C o latin small letter o U+006F p latin small letter p U+0070 r latin small letter r U+0072