[n] any of various parasites that live in the internal organs of animals (especially intestinal worms)
\En`to*zo"a\, n. pl. [NL., fr. Gr. ? within + ? an animal.] (Zo["o]l.)
1. A group of worms, including the tapeworms, flukes, roundworms, etc., most of which live parasitically in the interior of other animals; the Helminthes.
2. An artificial group, including all kinds of animals living parasitically in others.