Nematoidea \Nem`a*toi"de*a\, prop. n. pl. [NL., fr. Gr. nh^ma,
   nh`matos, thread + -oid.] (Zool.)
   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.
   [1913 Webster +PJC]

   Note: The trichina, stomach worm, and pinworm of man belong
         to this group. See also {Vinegar eel}, under {Vinegar},
         and {Gapeworm}.
         
[1913 Webster]