sphenoid

• POS: Adjective, Noun
• HYPHEN: sphe=noid

CIDE DICTIONARY

sphenoid, a. [Gr. ; sfh`n a wedge + e'i^dos form: cf. F. sphénoïde.].

•  Wedge-shaped; as, a sphenoid crystal.  [1913 Webster]
•  Of or pertaining to the sphenoid bone.  [1913 Webster]

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.

sphenoid, n. 

•  A wedge-shaped crystal bounded by four equal isosceles triangles. It is the hemihedral form of a square pyramid.  [1913 Webster]
•  The sphenoid bone.  [1913 Webster]

OXFORD DICTIONARY

sphenoid, adj. & n.
--adj.
1 wedge-shaped.
2 of or relating to the sphenoid bone.
--n. (in full sphenoid bone) a large compound bone forming the base of the cranium behind the eyes.

Derivative

sphenoidal adj.

Etymology

mod.L sphenoides f. Gk sphenoeides f. sphen wedge