What is "nematodea"

Nematoidea \Nem`a*toi"de*a\, prop. n. pl. [NL., fr. Gr. nh^ma, nh`matos, thread + -oid.] (Zo["o]l.) A phylum of worms, having a long, round, and generally smooth body; the roundworms. Called also Nematodea, and more commonly Nematoda. Formerly, it was classed as a taxonomic order.

Note: The trichina, stomach worm, and pinworm of man belong to this group. See also Vinegar eel, under Vinegar, and Gapeworm.