hippopotamus [ˌhɪpəˈpɒtəməs] (pl. hippopotamuses 或 hippopotami -mʌɪ)
a large thick-skinned semiaquatic African mammal, with massive jaws and large tusks 河马
Family Hippopotamidae: the very large Hippopotamus amphibius, frequenting rivers and lakes, and the smaller pygmy hippopotamus (Choeropsis liberiensis), frequenting forests near fresh water in West Africa 河马科:分常见于河流和湖泊的大河马和常见于淡水边森林的西非的倭河马(拉丁名 Choeropsis liberiensis)
语源
Middle English: via Latin from Greek hippopotamos, earlier hippos ho potamios 'river horse' (from hippos 'horse', potamos 'river')