The Collaborative International Dictionary of English v.0.48:

Cyon \Cy"on\ (s?"?n), n.
   See Cion, and Scion.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Cyon
    n 1: Asiatic wild dog [syn: Cuon, Cyon, genus Cuon, genus
         Cyon]