HIPPOPOTAMUS

noun (plural -muses or hippopotami) Etymology: Latin, from Greek hippopotamos, alteration of hippos potamios, literally, riverine horse Date: 1563 a very large herbivorous 4-toed chiefly aquatic artiodactyl mammal ( Hippopotamus amphibius ) of sub-Saharan Africa with an extremely large head and mouth, bare and very thick grayish skin, and short legs