Hippopotamus

[hip-uh-pot-uh-muh s] /ˌhɪp əˈpɒt ə məs/

noun, plural hippopotamuses, hippopotami
[hip-uh-pot-uh-mahy] /ˌhɪp əˈpɒt əˌmaɪ/ (Show IPA)
1.
a large herbivorous mammal, Hippopotamus amphibius, having a thick hairless body, short legs, and a large head and muzzle, found in and near the rivers, lakes, etc., of Africa, and able to remain under water for a considerable time.
/ˌhɪpəˈpɒtəməs/
noun (pl) -muses, -mi (-ˌmaɪ)
1.
a very large massive gregarious artiodactyl mammal, Hippopotamus amphibius, living in or around the rivers of tropical Africa: family Hippopotamidae. It has short legs and a thick skin sparsely covered with hair
2.
pigmy hippopotamus, a related but smaller animal, Choeropsis liberiensis
n.

1560s, from Late Latin hippopotamus, from Greek hippopotamus “riverhorse” (earlier ho hippos ho potamios “the horse of the river”), from hippos “horse” (see equine) + potamos “river, rushing water” (see potamo-). Replaced Middle English ypotame (c.1300), which is from the same source but via Old French. Glossed in Old English as sæhengest.

Ypotamos comen flyngynge. … Grete bestes and griselich [“Kyng Alisaunder,” c.1300]