The Collaborative International Dictionary of English v.0.48:

cestode \ces"tode\ (s[e^]s"t[=o]d), a. (Zool.)
   Of or pertaining to the Cestoidea. -- n. One of the
   Cestoidea.
   [1913 Webster]

WordNet (r) 3.0 (2006):

cestode
    n 1: ribbonlike flatworms that are parasitic in the intestines
         of humans and other vertebrates [syn: tapeworm,
         cestode]