Amoeb

Part of speech: noun

Definitions

1. A type of single-celled organism characterized by shapeless, moving pseudopods used for locomotion and feeding; a parasitic form causing disease in some hosts; a simple life form commonly found in aquatic or moist environments
2. An organism composed of a solitary cell that moves by extending parts of its body in a fluid manner; can be a harmless environmental microbe or a pathogenic parasite; known for its ability to alter shape continuously
3. A microscopic unicellular creature that propels itself by projecting cytoplasmic extensions; includes species that inhabit water and soil as well as those infecting animals and humans; noted for its flexible morphology and slow movement

Etymology: The word is "amoeba," the name for a single-celled organism that changes shape by extending false feet called pseudopods. It was coined in 1822 by the German naturalist Christian Gottfried Ehrenberg, who took the Greek "amoibē," meaning "change" or "exchange," and used it as a scientific name for these shifting creatures. The Greek noun itself came from "ameibein," "to change," so the name describes the organism's defining habit rather than any structure it has. The word was rendered in English as "amoeba," and the form "amœba" with a ligature was common in older texts. The singular is "amoeba," and the plural is "amoebae" or, in American usage, "amoebas."