amoeba

noun amoe·ba \ ə-ˈmē-bə \

variants: or less commonly ameba

Definition of amoeba

plural amoebas or amoebae play \-(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

or less commonly amebic \-bik\ adjective

See amoeba defined for English-language learners

See amoeba defined for kids

Recent Examples of amoeba from the Web

The most well known is the amoeba, but these microbes come in several forms, including species that move with a single flagellum or with hairlike cilia.

— adrian higgins, idahostatesman, "The zoo beneath our feet: We’re only beginning to understand soil’s hidden world," 23 Aug. 2017
One: amoeba fronts and complex five-man blitzes on passing downs.

— andy benoit, SI.com, "Tennessee Titans: 10 Things You Need to Know," 11 Aug. 2017
The Iran native thrived in study of curved surfaces such as doughnut shapes and amoebas -- to a degree that other bright minds in the field dared not explore, her colleagues have said.

— jason hanna, CNN, "Maryam Mirzakhani, only woman to take math's highest award, dies at 40," 15 July 2017
The Louisiana Department of Health told water and town officials Thursday that the amoeba was detected in Terrebonne Parish, according to the New York Post.

— Fox News, "Brain-eating amoeba found in Louisiana drinking water, officials say," 30 June 2017
Residents should continue the precautions until testing no longer confirms the presence of the amoeba.

— CBS News, "Brain-eating amoeba detected in La. water system," 29 June 2017
The amoeba is transferred to victims, the CDC reports, through water entering the nose while swimming in warm lakes and rivers.

— tim evans, USA TODAY, "Who's to blame for lake's brain-eating amoeba? Appeals court wades into negligence lawsuit," 23 June 2017
The amoeba is transferred to victims, the CDC reports, through water entering the nose while swimming in warm lakes and rivers.

— tim evans, Indianapolis Star, "Who's to blame for lake's brain-eating amoeba? Appeals court wades into negligence lawsuit," 22 June 2017
Water samples taken from the whitewater center after her death tested positive for the amoeba.

— leada gore, AL.com, "67 Alabama counties, ranked from most to least-populated," 21 June 2017

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.

Illustration of amoeba

Origin and Etymology of amoeba

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

NEW! Time Traveler

First Known Use: 1822

See Words from the same year

AMOEBA Defined for English Language Learners

amoeba

noun

Definition of amoeba for English Language Learners

: a tiny living thing that consists of a single cell

AMOEBA Defined for Kids

amoeba

noun amoe·ba \ ə-ˈmē-bə \

Definition of amoeba for Students

plural amoebas or amoebae \-bē\

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

Medical Dictionary

amoeba

noun 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