megathere megasynthetic • megatherian · · · Info · Definitions · Synonyms · Characters · · megathere · · Text Latin · · Script 9 · · Length Definitions · · · (noun) gigantic extinct terrestrial sloth-like mammal of the Pliocene and Pleistocene in America. Synonyms: ground sloth. · · Noun Definition 1 Synonyms · · · ground sloth · · Synonym 1 Characters · · a latin small letter a U+0061 e latin small letter e U+0065 g latin small letter g U+0067 h latin small letter h U+0068 m latin small letter m U+006D r latin small letter r U+0072 t latin small letter t U+0074