sphenoid

from WordNet (r) 3.0 (2006)

sphenoid
    n 1: butterfly-shaped bone at the base of the skull [syn:
         {sphenoid bone}, {sphenoid}, {os sphenoidale}]

from The Collaborative International Dictionary of English v.0.48

Sphenoid \Sphe"noid\, a. [Gr. ???; sfh`n a wedge + e'i^dos form:
   cf. F. sph['e]no["i]de.]
   1. Wedge-shaped; as, a sphenoid crystal.
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   2. (Anat.) Of or pertaining to the sphenoid bone.
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   {Sphenoid bone} (Anat.), an irregularly shaped bone in front
      of the occipital in the base of the skull of the higher
      vertebrates. It is composed of several fetal bones which
      become united the adult. See {Alisphenoid},
      {Basisphenoid}, {Orbitosphenoid}, {Presphenoid}.
      [1913 Webster]

from The Collaborative International Dictionary of English v.0.48

Sphenoid \Sphe"noid\, n.
   1. (Crystallog.) A wedge-shaped crystal bounded by four equal
      isosceles triangles. It is the hemihedral form of a square
      pyramid.
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   2. (Anat.) The sphenoid bone.
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