amoeba

play

noun amoe·ba \ə-ˈmē-bə\

variants: or less commonly

ameba

Definition of amoeba

plural

amoebas

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

play 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

Despite the oceanic source, the virus grew nicely in fresh water amoebae.

— ars technica, WIRED, "Megavirus May Be Stripped-Down Version of Normal Cell", 11 Oct. 2011

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

First Known Use: 1822

AMOEBA Defined for English Language Learners

amoeba

play

noun

Definition of amoeba for English Language Learners

: a tiny living thing that consists of a single cell

AMOEBA Defined for Kids

amoeba

play

noun amoe·ba \ə-ˈmē-bə\

Definition of amoeba for Students

plural

amoebas

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 plural amoebas or amoebae \-(ˌ)bē\ play : a protozoan of the genus Amoeba; broadly : an amoeboid protozoan (as a naked rhizopod)