The Collaborative International Dictionary of English v.0.48:

cheekbone \cheekbone\ n.
   the arch of bone beneath the eye that forms the prominence of
   the cheek.

   Syn: zygomatic bone, malar bone, jugal bone, os zygomaticum.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

cheekbone
    n 1: the arch of bone beneath the eye that forms the prominence
         of the cheek [syn: cheekbone, zygomatic bone,
         zygomatic, malar, malar bone, jugal bone, os
         zygomaticum]