upper carboniferous period upper carboniferous • uppercase · · · Info · Definitions · Characters · · upper carboniferous period · · Text Common · · Latin · · Scripts 26 · · Length 9 · · Syllables Definitions · · · (noun) from 310 million to 280 million years ago; warm climate; swampy land. Synonyms: Pennsylvanian, Pennsylvanian period, Upper Carboniferous, Upper Carboniferous period. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 b latin small letter b U+0062 c latin small letter c U+0063 d latin small letter d U+0064 e latin small letter e U+0065 f latin small letter f U+0066 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 s latin small letter s U+0073 u latin small letter u U+0075