\Nem`a*toi"de*a\, n. pl. [NL., fr. gr. ?, ?, thread +
-oid.] (Zo["o]l.)
An order of worms, having a long, round, and generally smooth
body; the roundworms. they are mostly parasites. Called also
{Nematodea}, and {Nematoda}.
Note: The trichina, stomach worm, and pinworm of man belong
      to this group. See also {Vinegar eel}, under {Vinegar},
      and {Gapeworm}.