12 letters · 23 points in Scrabble
noun massive thick-skinned herbivorous animal living in or around rivers of tropical Africa
originFrom 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 native Old English sǣhenġest, and largely displaced English nicker (from native Old English nicor) and river horse.
Etymology from Wiktionary, CC BY-SA 3.0