a large, amphibious, herbivorous mammal (hippopotamus amphibius), common in the rivers of africa. it is allied to the hogs, and has a very thick, naked skin, a thick and square head, a very large muzzle, small eyes and ears, thick and heavy body, and short legs. it is supposed to be the behemoth of the bible. called also zeekoe, and river horse. a smaller species (h. liberiencis) inhabits western africa.