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
amoebicplay or less commonly
Recent Examples of amoeba from the Web
Despite the oceanic source, the virus grew nicely in fresh water amoebae.
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.
AMOEBA Defined for English Language Learners
Definition of amoeba for English Language Learners
: a tiny living thing that consists of a single cell
AMOEBA Defined for Kids
Definition of amoeba for Students
: a tiny water animal that is a single cell which flows about and takes in food
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)
amoebic\-bik\ play adjective
Seen and Heard
What made you want to look up amoeba? Please tell us where you read or heard it (including the quote, if possible).