hippopotamus Definition

any of a family (Hippopotamidae) of very large, four-toed, chiefly aquatic, herbivorous artiodactyl mammals having a very large head and mouth, nearly hairless thick grayish skin, long lower canine teeth, and relatively short legs, and including two living species:

one (Hippopotamus amphibius) of sub-Saharan Africa that has webbing between the toes, spends most of the day in or near water, and typically weighs between 3 to 4 tons (2700 to 3600 kilograms)

pygmy hippopotamus

a small hippopotamus (Hexaprotodon liberiensis synonym Choeropsis liberiensis) of western Africa and especially Liberia that may reach a weight of nearly 600 pounds (270 kilograms)