Sphe‐neth″moid (?), a. [Sphenoid + ethmoid.] (Anat.) Of or pertaining to both the sphenoidal and the ethmoidal regions of the skull, or the sphenethmoid bone; sphenethmoidal.
Sphenethmoid bone(Anat.), a bone of the skull which surrounds the anterior end of the brain in many amphibia; the girdle bone.