hippopotamus
Americannoun
noun
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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
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a related but smaller animal, Choeropsis liberiensis
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
Derived Forms
Inflected Forms
Nouns
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
Explanation
A hippopotamus is a huge African mammal that spends time in the water and on land. These herbivores are so enormous that one hippopotamus can eat two pounds of grass in a single feeding. Although they're plant-eaters, hippopotamuses are powerfully strong and fiercely protective. Experts consider them to be unpredictable as well, and if you happen to be in sub-saharan Africa, it's smart to keep your distance! Hippopotamus is from the Greek ho hippos potamios, "the horse of the river," and its roots, hippos, "horse," and potamos, "rushing water."
Vocabulary lists containing hippopotamus
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
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
Water Lily, a 45-year-old female hippopotamus who has lived at the Woodland Park Zoo since 1979, will be euthanized next week.
From Seattle Times ● Apr. 26, 2024
A zoo in Japan has confirmed that a hippopotamus thought for seven years to be a he is, in fact, a she.
From BBC ● Apr. 23, 2024
All six-thousand hippopotamus pounds of Fry dive for my ankles.
From "I'll Give You the Sun" by Jandy Nelson
Their list mainly included fish, but also mammals like beavers, river dolphins and hippopotami, as well as coldblooded creatures like crocodiles, giant salamanders and alligator snapping turtles.
From New York Times ● Jan. 21, 2020
Sometimes he dances, rather in the manner of the tutu-clad hippopotami in Walt Disney’s “Fantasia.”
From New York Times ● Mar. 18, 2016
The woman turned out to be Rebecca Francis, winner of the 2010 reality show Extreme Huntress, whose website features a gallery of the animals she’s hunted – from hippopotami in Mozambique to moose in Alaska.
From The Guardian ● Jul. 29, 2015
"But such pedantry is frowned upon in common usage, so we are stuck with the equally accepted hippopotamuses and hippopotami."
From The Guardian ● Jun. 11, 2010
Of all the myriad hosts of wonderful wild creatures that until lately populated these desert plains and mountains, only this one school of hippopotami and a few hundred springbuck survive.
From Lodges in the Wilderness by Scully, W. C. (William Charles)
The animals said to have been featured in various Roman spectacles include hippopotamuses, elephants, rhinoceroses, bears, ostriches and big cats like lions and tigers.
From Los Angeles Times ● Nov. 22, 2024
They confront many obstacles and dangers on their trek, including rivers that hide dangerous hippopotamuses and crocodiles, not to mention numerous predators they face on land.
From Textbooks ● Apr. 19, 2023
In addition to India and Mexico, facilities in Ecuador, Botswana, and the Philippines have expressed interest in acquiring some Colombian hippopotamuses.
From Washington Times ● Mar. 2, 2023
The authors describe parasitoid wasps that lay their eggs inside the cocoons of other parasitoid wasps, for example, and leeches that spend their entire lives inside the anuses of hippopotamuses.
From Scientific American ● Nov. 17, 2022
The hippopotamuses continued to doze with their noses above the surface.
From "A Girl Named Disaster" by Nancy Farmer
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
