The Collaborative International Dictionary of English v.0.48:

Chelate \Che"late\, a. (Zool.)
   Same as Cheliferous.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

chelate \che"late\, n. (Chem.)
   a compound formed by combination of a metal ion in solution
   with a compound containing heteroatoms (such as oxygen or
   nitrogen), in which at least two heteroatoms are bound to the
   metal. The bonds may be covalent or non-covalent. Chelates in
   some cases have very low dissociation constants, and organic
   compounds (chelating agents) which form such chelates are
   therefore used to reduce the concentration of free metal ions
   in solution.
   [PJC]

WordNet (r) 3.0 (2006):

chelate
    adj 1: relating to or characterized by chelation [syn:
           chelate, chelated]
    2: having or resembling chelae or claws
    n 1: a heterocyclic compound having a metal ion attached by
         coordinate bonds to at least two nonmetal ions [syn:
         chelate, chelate compound]
    v 1: form a chelate, in chemistry