ameba: Meaning and Definition of

a•me•ba

1. any of numerous freshwater, marine, or parasitic one-celled protozoa of the order Amoebida, characterized by a granular nucleus surrounded by a jellylike mass of cytoplasm that forms temporary extensions, or pseudopodia, by which the organism moves, engulfs food particles, and forms food vacuoles.
2. a protozoan of the genus Amoeba, inhabiting bottom vegetation of freshwater ponds and streams: used widely in laboratory studies.