Source : Webster's Revised Unabridged Dictionary (1913)

Nematoidea \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}.