amoeba

noun

amoe·​ba ə-ˈmē-bə 

variants or less commonly ameba

plural amoebas or amoebae also amebas or amebae ə-ˈmē-(ˌ)bē 

: 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

• 1 pseudopodium
• 2 nucleus
• 3 contractile vacuole
• 4 food vacuole

Examples of amoeba in a Sentence

Recent Examples on the Web

View More How a Texas oil executive persuaded the Biden administration with ambitious ‘net zero oil’ Arlington closes pools, splash pads after test appears positive for brain-eating amoeba Dinosaur tracks from 113 million years ago newly revealed by Texas drought . —Isabella Volmert, Dallas News, 31 Aug. 2023

Earlier this month, the Nevada Division of Public and Behavioral Health said a 2-year-old boy died from a brain-eating amoeba infection likely contracted at a natural hot spring. —Raja Razek, CNN, 30 July 2023

Brain-eating amoeba is most commonly found in warm fresh waters such as lakes, rivers and hot springs. —Vanessa Etienne, Peoplemag, 20 July 2023

While the risk of infection is rare, the amoeba is incredibly lethal. —Gabe Hauari, USA TODAY, 31 July 2023

While extremely rare, Naegleria fowleri — or brain-eating amoeba — can cause an almost always fatal infection, according to the CDC A 2-year-old boy has died one week after battling Naegleria fowleri, or brain-eating amoeba. —Vanessa Etienne, Peoplemag, 20 July 2023

However, it was later determined that the toddler’s symptoms were a result of brain eating amoeba. —Vanessa Etienne, Peoplemag, 20 July 2023

But it was later discovered that Woodrow’s symptoms were linked to brain-eating amoeba. —David Chiu, Peoplemag, 31 July 2023

Among known infections since 1962, only four people have survived the amoeba, resulting in a 97% fatality rate. —Gabe Hauari, USA TODAY, 31 July 2023

See More

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

Kids Definition

amoeba

noun

amoe·​ba

variants also ameba

ə-ˈmē-bə

plural amoebas or amoebae -(ˌ)bē 

: 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

-bik 

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  also amebas or amebae : a protozoan of the genus Amoeba

broadly : an amoeboid protozoan (as a naked rhizopod)

amebic adjective

or amoebic

-bik