Sphe″noid (?), a. [Gr. ���; σφήν a wedge + εἰ̑δοσ form: cf. F. sphénoïde.] 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.