noun, plural hip·po·pot·a·mus·es, hip·po·pot·a·mi [hip-uh-pot-uh-mahy] /ˌhɪp əˈpɒt əˌmaɪ/.
Origin of hippopotamus
Examples from the Web for hippopotami
As usual with hippopotami, whether dead or alive, he disappeared beneath the water at the shot.In the Heart of Africa|Samuel White Baker
On the last occasion that I visited him he was preparing for a hunt against the hippopotami, which were in a lake near his kraal.The White Chief of the Caffres|A.W. Drayson
One of the opposition shows was making a great feature of a pair of hippopotami, or river horses, from the Nile.Sawdust & Spangles|W. C. Coup
Then Caliph, the patriarch of all the hippopotami, joined his voice to that of the old lion.Two in a Zoo|Curtis Dunham
This lake is probably several miles in length, and swarms with hippopotami and crocodiles.How I Found Livingstone|Henry M. Stanley
British Dictionary definitions for hippopotami
noun plural -muses or -mi (-ˌmaɪ)
Word Origin for hippopotamus
Word Origin and History for hippopotami
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]