The Collaborative International Dictionary of English v.0.48:

Pterygoid \Pter"y*goid\, a. [Gr. ?, ?, a wing + -oid.] (Anat.)
   (a) Like a bird's wing in form; as, a pterygoid bone.
   (b) Of, pertaining to, or in the region of, the pterygoid
       bones, pterygoid processes, or the whole sphenoid bone.
       -- n. A pterygoid bone.
       [1913 Webster]

   Pterygoid bone (Anat.), a bone which corresponds to the
      inner plate of the pterygoid process of the human skull,
      but which, in all vertebrates below mammals, is not
      connected with the posterior nares, but serves to connect
      the palatine bones with the point of suspension of the
      lower jaw.

   Pterygoid process (Anat.), a process projecting downward
      from either side of the sphenoid bone, in man divided into
      two plates, an inner and an outer. The posterior nares
      pass through the space, called the pterygoid fossa,
      between the processes.
      [1913 Webster]