hippopotamus /ˌhɪpəˈpɑːtəməs/ noun plural hippopotamuses or hippopotami /-ˌmaɪ/ /ˌhɪpəˈpɑːtəˌmaɪ/ plural hippopotamuses or hippopotami /-ˌmaɪ/ /ˌhɪpəˈpɑːtəˌmaɪ/ Learner's definition of HIPPOPOTAMUS
[count]
: a large African animal that has an extremely large head and mouth and short legs and that spends most of its time in water河马