SPHENETHMOID

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.