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amoeba

American  
[uh-mee-buh] / əˈmi bə /

noun

plural

amoebas, amoebae
  1. a variant of ameba.


amoeba British  
/ əˈmiːbə /

noun

  1. any protozoan of the phylum Rhizopoda , esp any of the genus Amoeba, able to change shape because of the movements of cell processes (pseudopodia). They live in fresh water or soil or as parasites in man and animals

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

amoeba Scientific  
/ ə-mēbə /

plural

amoebas
  1. Any of various one-celled aquatic or parasitic protozoans of the genus Amoeba or related genera, having no definite form and consisting of a mass of protoplasm containing one or more nuclei surrounded by a flexible outer membrane. Amoebas move by means of pseudopods.


amoeba Cultural  
  1. An animal composed of only one cell that has no fixed shape. It is the best known of the single-celled animals, or protozoa.


Discover More

The term amoeba is sometimes used to refer to something with an indefinite, changeable shape.

Other Word Forms

  • amoebic adjective

Etymology

Origin of amoeba

C19: from New Latin, from Greek amoibē change, from ameibein to change, exchange

Compare meaning

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Explanation

An amoeba is a tiny, single-celled organism. You need a powerful microscope to see an amoeba. An amoeba is distinguished by the fact that it has only one cell, and that the shape of its body is vague and irregular. An amoeba stretches and changes shape as it moves, and reproduces by splitting itself in two. The amoeba was discovered in 1757 and named almost 100 years later, from the Greek root amoibe, or "change."

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Vocabulary lists containing amoeba

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

In fact, they immediately set themselves on the task of pleasing Carol and those like her, along with solving the riddle of their immunity, so they can absorb the stragglers into their joy amoeba.

From Salon • Nov. 26, 2025

From a bejeweled Elvis jumpsuit to a look made entirely of neon green tassels meant to resemble an amoeba, her vision was avant-garde, playful and undeniably multidimensional.

From Los Angeles Times • Oct. 13, 2025

"Even a 1C rise can trigger its spread in Kerala's tropical climate and water pollution fuels it further by feeding bacteria the amoeba consumes," says Prof Anish.

From BBC • Sep. 17, 2025

Naegleriaviruses are taken up mistakenly as a food source but destroy their amoeba hosts within just few hours.

From Science Daily • Apr. 24, 2024

The spot where he usually parked one of his carts was empty; a huge amoeba of oil stained the concrete floor.

From "Tradition" by Brendan Kiely