The Collaborative International Dictionary of English v.0.48:

Gordiacea \Gor`di*a"ce*a\, n. pl. [NL. See Gordian, 1.]
   (Zool.)
   A division of nematoid worms, including the hairworms or hair
   eels (Gordius and Mermis). See Gordius, and
   Illustration in Appendix.
   [1913 Webster]