What is "sphenoid bone"

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.

2. (Anat.) Of or pertaining to the sphenoid bone.

   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.

n. A compound bone at the base of the skull behind the eyes.

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

The sphenoid bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the temporal bone and the basilar part of the occipital bone. The sphenoid bone is one of the seven bones that articulate to form the orbit. Its shape somewhat resembles that of a butterfly or bat with its wings extended.