Petrosal adj. (Anat.) (a)Hard; stony; petrous; as, the petrosal bone; petrosal part of the temporal bone.
(b)Of, pertaining to, or in the region of, the petrous, or petrosal, bone, or the corresponding part of the temporal bone.
Petrosal bone (Anat.), a bone corresponding to the petrous portion of the temporal bone of man; or one forming more or less of the periotic capsule.