therian/ˈθɪɹ.i.ən/EtymologyFrom translingual Theria + -ian. From Ancient Greek θηρίον (thēríon, “wild beast”).therian means of or pertaining to the taxonomic subclass Theria. Lexicurio rates it Sui generis — a strength score of 87 out of 100.adjOf or pertaining to the taxonomic subclass Theria.nounAny member of the taxonomic subclass Theria, the placental and marsupial mammals.