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hippopotamus

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

noun

  • hippopotamuses,
    plural
  • hippopotami
    plural
  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.


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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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."

Keep Reading on Vocabulary.com

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:

Aesthetes had been howling about the Freedom 250 set, a soaring, 92-foot tall structure which resembled one of those arcade machine claws in which you try and fail to grab a stuffed hippopotamus.

From The Wall Street Journal Jun. 15, 2026

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

From Science Daily Oct. 26, 2025

A baby hippopotamus is causing a fan frenzy in Thailand.

From BBC Sep. 13, 2024

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

For her part, Rosie is carted out through each town in the hippopotamus wagon and then displayed in the menagerie.

From "Water for Elephants" by Sara Gruen

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

The idea of a family of hippopotami walking upright on two legs?

From The Guardian Apr. 13, 2019

Sometimes he dances, rather in the manner of the tutu-clad hippopotami in Walt Disney’s “Fantasia.”

From New York Times Mar. 18, 2016

"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

That night they encamped at Lake Musunya, which swarmed with hippopotami.

From Stanley's Adventures in the Wilds of Africa A Graphic Account of the Several Expeditions of Henry M. Stanley into the Heart of the Dark Continent by Joel Tyler Headley

Nevertheless, the rainforest is rich in biodiversity, including pygmy hippopotamuses, giant forest hogs, canopy monkeys, and chimpanzees, as well as thousands of species of plants.

From Textbooks Apr. 19, 2023

Animal sanctuary facilities in India and Mexico have agreed to take in 70 invasive African hippopotamuses that descend from those once owned by Colombian drug lord Pablo Escobar.

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

A mural depicts the entry to his infamous rural getaway, Hacienda Napoles, which featured, among other attractions, a zoo from which imported hippopotamuses have since escaped into the nearby countryside, causing environmental havoc.

From Los Angeles Times Oct. 10, 2022

I mean wild, like tigers and bears and hippopotamuses.

From "The World According to Humphrey" by Betty G. Birney

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