amoeba

American  

[uh-mee-buh] / əˈmi bə /

noun

plural

amoebas, amoebae

1. a variant of ameba.

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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

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amoeba Scientific  

/ ə-mē′bə /

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.

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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.

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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

How does amoeba compare to similar and commonly confused words? Explore the most common comparisons:

• amoeba vs. paramecium

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."

Example Sentences

Its undulating form has earned its share of abuse, and it has been compared to a pancake or an amoeba.

From The Wall Street Journal • Apr. 17, 2026

"It's not fungi, it's not a plant, it's not animal. It's more closely related to an amoeba," Barry explains.

From BBC • Dec. 29, 2025

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

In the meter stick analogy, amplifying the signal makes the amoeba appear larger so that even coarse measurement markings can capture it accurately.

From Science Daily • Nov. 11, 2025

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