hippopotamus

American  

[hip-uh-pot-uh-muhs] / ˌhɪp əˈpɒt ə məs /

noun

plural

hippopotamuses, hippopotami

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.

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hippopotamus British  

/ ˌhɪpəˈpɒtəməs /

noun

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. a related but smaller animal, Choeropsis liberiensis

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Usage

Plural word for hippopotamus The plural form of hippopotamus can be either hippopotamuses or hippopotami. Hippopotamuses is more widely used. The plurals of several other singular words ending in -us are also formed this way, such as virus/viruses, sinus/sinuses, and walrus/walruses. Irregular plurals that are formed like hippopotami, such as cactus/cacti and fungus/fungi, derive directly from their original pluralization in Latin. However, the standard English plural -es ending is often also acceptable for these terms, as in cactuses.

Other Word Forms

• hippopotamian adjective
• hippopotamic adjective

Etymology

Origin of hippopotamus

1555–65; < Latin < Greek hippopótamos, earlier híppos potámios literally, riverine horse (term used by Herodotus in his account of the Egyptian hippopotamus); compare Middle English ypotame, ypotamos, ypotanus < Old French ypotame < Medieval Latin ypotamus

Example Sentences

A $31.4 million bar cart shaped like a hippopotamus.

From The Wall Street Journal • Dec. 17, 2025

Researchers examined numerous hippopotamus fossils using both genetic and radiocarbon dating methods.

From Science Daily • Oct. 26, 2025

An "incredibly rare" female baby hippopotamus has been born at Edinburgh Zoo.

From BBC • Nov. 5, 2024

The hippopotamus, often simply referred to as a hippo, is a creature that fascinates and delights those who are fortunate enough to witness it in its natural habitat.

From Salon • Mar. 22, 2024

“Though of course we both have our natural beauty, as the hippopotamus said to the rat.”

From "The Golden Goblet" by Eloise Jarvis McGraw