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."

Definitions of amoeba
  1. noun
    naked freshwater or marine or parasitic protozoa that form temporary pseudopods for feeding and locomotion
    synonyms: ameba
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    any ameba of the genus Endamoeba
    Endamoeba histolytica
    the parasitic ameba that causes amebic dysentery in human beings
    type of:
    rhizopod, rhizopodan
    protozoa characterized by a pseudopod
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