资料来源 : Webster's Revised Unabridged Dictionary (1913)

Presphenoid \Pre*sphe"noid\, a. (Anat.)
   Situated in front of the sphenoid bone; of or pertaining to
   the anterior part of the sphenoid bone (i. e., the
   presphenoid bone).

   {Presphenoid bone} (Anat.), the anterior part of the body of
      the sphenoid bone in front of the basisphenoid. It is
      usually a separate bone in the young or fetus, but becomes
      a part of the sphenoid in the adult.