amoeba

noun

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)
: 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
amoebic adjective
or less commonly amebic
ə-ˈmē-bik

Illustration of amoeba

Illustration of amoeba
  • 1 pseudopodium
  • 2 nucleus
  • 3 contractile vacuole
  • 4 food vacuole

Examples of amoeba in a Sentence

Recent Examples on the Web Water that has undergone filtration to eliminate the Naegleria bacteria, a waterborne amoeba that can cause illness. Caroline Thomason, Verywell Health, 15 Dec. 2023 The swimmer developed amebic meningitis infection, which is caused by Naegleria fowleri, more commonly known as a brain-eating amoeba, after swimming in Lake Lyndon B. Johnson in August, according to Austin Public Health. Aliza Chasan, CBS News, 30 Aug. 2023 What is Naegleria fowleri, or a brain-eating amoeba? Isabelle Butera, USA TODAY, 14 June 2023 Naegleria fowleri is a microscopic amoeba that lives in warm freshwater, such as lakes, ponds and rivers. Avery Hurt, Discover Magazine, 3 Oct. 2023 The unidentified victim was infected with Naegleria fowleri, an amoeba that destroys brain tissue, causes brain swelling and usually death, the Georgia Department of Health said in a news release Friday. CBS News, 31 July 2023 The amoeba thrives in warm water, growing best in July, August and September, the CDC says. Sarah Rumpf-Whitten, Fox News, 13 Oct. 2023 So, the risk of having your brain dissolved by a rogue amoeba is very low. Avery Hurt, Discover Magazine, 3 Oct. 2023 Naegleria fowleri is an amoeba that lives in soil and warm freshwater lakes, rivers, ponds and hot springs. Christina Zdanowicz, CNN, 15 Sep. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'amoeba.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

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

First Known Use

1822, in the meaning defined above

Time Traveler
The first known use of amoeba was in 1822

Dictionary Entries Near amoeba

Cite this Entry

“Amoeba.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/amoeba. Accessed 19 Mar. 2024.

Kids Definition

amoeba

noun
amoe·​ba
variants also ameba
ə-ˈmē-bə
plural amoebas or amoebae -(ˌ)bē How to pronounce amoeba (audio)
: any of a large genus of protozoans that have no permanent cell organs or structures, that change shape to form temporary lobes for moving and taking in food, and that are widespread in fresh and salt water and in moist soils
amoebic adjective

Medical Definition

amoeba

noun
amoe·​ba
ə-ˈmē-bə
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)
amebic adjective
or amoebic

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