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

Examples of amoeba in a Sentence

Recent Examples on the Web Exciting news from the world of interchangeable banking institutions: TCF, a name that boomers associate with a hundred time-and-temp signs, has been absorbed by a financial amoeba, and the old local name will be lost. Star Tribune, "Lileks: Another local name, kaput," 18 Dec. 2020 Although most only result in mild gastrointestinal upsets, some can be deadly, as witnessed by recent reports of brain-eating amoeba in Texas municipal water supply. Lynne Peeples Ensia, Smithsonian Magazine, "Why Reports of Legionnaires’ Disease Are on the Rise in the United States," 22 Oct. 2020 The amoeba then travels to the brain and can potentially cause primary amebic meningoencephalitis, which is usually fatal. CBS News, "Texas governor issues disaster declaration over brain-eating amoeba found in Lake Jackson water supply," 28 Sep. 2020 Governor Greg Abbott issued a disaster declaration on Sunday after testing found the brain-eating amoeba in the water supply. Jordan Freiman, CBS News, "Texas officials say it could take 2-3 months to make water safe after brain-eating amoeba kills 6-year-old," 29 Sep. 2020 When freshwater and poorly chlorinated swimming pools heat up, the dangerous amoeba Naegleria fowleri can kill you. Richard Tribou,, "Parents of Florida boy say he died from brain-eating amoeba: report," 12 June 2015 The water-loving amoeba is often found in warm lakes, rivers and host springs. Washington Post, "Brain-eating amoeba in water supply kills 6-year-old, leads Texas city to declare a disaster," 28 Sep. 2020 The amoeba can cause a rare infection of the brain called primary amebic meningoencephalitis (PAM) that destroys brain tissue and is usually fatal. Fox News, "Brain-eating amoeba in water supply spurs Texas city to declare disaster after boy, 6, dies," 27 Sep. 2020 If your tortilla is turning out more amoeba-shaped than round, embrace the irregularity. Washington Post, "How to make light, chewy, flavor-packed flour tortillas at home," 15 Oct. 2020

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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Time Traveler for amoeba

Time Traveler

The first known use of amoeba was in 1822

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Statistics for amoeba

Last Updated

6 Jan 2021

Cite this Entry

“Amoeba.” Dictionary, Merriam-Webster, Accessed 25 Jan. 2021.

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More Definitions for amoeba


How to pronounce amoeba (audio)

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 amoeba (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 amoeba (audio) \ adjective

More from Merriam-Webster on amoeba

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

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