amoe·​ba | \ ə-ˈmē-bə How to pronounce amoeba (audio) \
variants: or less commonly
plural amoebas or amoebae\ -​(ˌ)bē How to pronounce amoebae (audio) \

Definition of amoeba

: any of a large genus (Amoeba) of naked rhizopod protozoans with lobed and never anastomosing pseudopodia, without permanent organelles or supporting structures, and of wide distribution in fresh and salt water and moist terrestrial environments broadly : a naked rhizopod or other amoeboid protozoan

Illustration of amoeba

Illustration of amoeba

amoeba: 1 pseudopodium, 2 nucleus, 3 contractile vacuole, 4 food vacuole

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Other Words from amoeba

amoebic or less commonly amebic \ -​bik \ adjective

Examples of amoeba in a Sentence

Recent Examples on the Web

Naegleria fowleri, known as the brain-eating amoeba, caused Gray's death, the North Carolina Department of Health and Human Services said in a press release. Madeline Holcombe, CNN, "Brain-eating amoeba kills man who went swimming at North Carolina water park," 26 July 2019 Health officials say the amoeba is known to have infected just 145 people in the U.S. from 1962 through 2018. CBS News, "Brain-eating amoeba kills man after North Carolina water park visit," 26 July 2019 Lakshmi adds that freshwater can also be home to potentially dangerous amoeba, albeit very rarely. Jamie Ducharme, Time, "Your Summer Beach Trip Could Put You at Risk of Getting Sick. Here's What You Need to Know," 24 July 2019 The eye infection is caused by a microscopic, free-living amoeba called Acanthamoeba that's commonly found in water and soil. NBC News, "Woman nearly loses sight in one eye after wearing contacts in shower and pool," 17 July 2019 Nearly 40 years ago, scientists discovered that an amoeba called Paulinella chromatophora plays host to a photosynthetic structure that in some ways resembles cyanobacteria, the original ancestors of chloroplasts. Quanta Magazine, "Tiny Genomes May Offer Clues to First Plants and Animals," 20 June 2013 The Tour de France peloton, the amoeba-like mass of more than 100 cyclists who ride fast and hip-to-hip, had come to one of the ubiquitous roundabouts when Pinot and his team made a split-second decision to go left instead of right. Michael Powell, New York Times, "On the Road With the Tour de France," 18 July 2019 Acanthamoeba keratitis occurs when the amoeba makes its way onto a person's cornea. NBC News, "Woman nearly loses sight in one eye after wearing contacts in shower and pool," 17 July 2019 One looked like a giant chicken, another like a turtle and another still like an amoeba. Mark Lamster, Dallas News, "The epic tale of the House of the Century, the trippy Texas icon that defies polite description," 12 July 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'amoeba.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of amoeba

1822, in the meaning defined above

History and Etymology for amoeba

New Latin, genus name, from Greek amoibē change, from ameibein to change — more at migrate

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Statistics for amoeba

Last Updated

7 Aug 2019

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Time Traveler for amoeba

The first known use of amoeba was in 1822

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English Language Learners Definition of amoeba

: a tiny living thing that consists of a single cell


amoe·​ba | \ ə-ˈmē-bə How to pronounce amoeba (audio) \
plural amoebas or amoebae\ -​bē \

Kids Definition of amoeba

: a tiny water animal that is a single cell which flows about and takes in food


amoe·​ba | \ ə-ˈmē-bə\

Medical Definition of amoeba

1 capitalized : a large genus of naked rhizopod protozoans that have lobed and never anastomosing pseudopodia and are widely distributed in fresh and salt water and moist terrestrial environments
2 also ameba plural amoebas or amoebae\ -​(ˌ)bē How to pronounce amoebae (audio)\ also amebas or amebae : a protozoan of the genus Amoeba broadly : an amoeboid protozoan (as a naked rhizopod)

Other Words from amoeba

amebic or amoebic \ -​bik How to pronounce amoebic (audio) \ adjective

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More from Merriam-Webster on amoeba

Rhyming Dictionary: Words that rhyme with amoeba

Spanish Central: Translation of amoeba

Nglish: Translation of amoeba for Spanish Speakers Encyclopedia article about amoeba

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a period when something is suspended

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