hippopotamus

From Latin and New Latin hippopotamus, from Ancient Greek ἱπποπόταμος (hippopótamos), from ἵππος (híppos, “horse”) (English hippo-) + ποταμός (potamós, “river”). First attested in the 1560s. Displaced displaced English nicker (from native Old English nicor) and river horse.

出典: Wiktionary「hippopotamus」（CC BY-SA 4.0）