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

Because the band really is like an amoeba, constantly changing. San Diego Union-Tribune, "Lyle Lovett, with or without Hazmat suit, set to light up for Fourth of July," 26 June 2019 Take the social amoeba Dictyostelium discoideum, which has three: Each type can mate with members of the other two. Quanta Magazine, "Why Nature Prefers Couples, Even for Yeast," 17 July 2018 The smallest of amoebas might be able to cram themselves in, with a diameter of just a few micrometers themselves. Avery Thompson, Popular Mechanics, "Scientists Build the Tiniest House in the World," 25 July 2018 Instinctively, the amoeba would extend tendrils into the channels to try and get the food. Avery Thompson, Popular Mechanics, "A Single Cell Hints at a Solution to the Biggest Problem in Computer Science," 27 Dec. 2018 These crippling and even fatal diseases include African sleeping sickness, a brain-eating amoeba, hookworm, roundworms that infiltrate the lymphatic system, and malaria. Bradley J. Fikes,, "UCSD steps up fight against tropical parasitical diseases," 4 July 2018 Tragically, Minnesota has seen two fatalities in children caused from a waterborne amoeba that enters the nose and attacks the brain. Glenn Howatt,, "Swimming pools, hot tubs are more likely than lakes to make you sick, studies find," 11 July 2018 These include a species of a brain-eating amoeba that can legally be grown in animal models at only two places in the U.S., the Centers for Disease Control and Prevention in Atlanta, and UCSD. Bradley J. Fikes,, "UCSD steps up fight against tropical parasitical diseases," 4 July 2018 This marks the third time the amoeba has been detected in the water since 2015. CBS News, "Brain-eating amoeba found in Louisiana water district for third time since 2015," 13 June 2018

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

10 Jul 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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