| Basisphenoidal | { } a. [ Basi- + sphenoid. ] (Anat.) Of or pertaining to that part of the base of the cranium between the basioccipital and the presphenoid, which usually ossifies separately in the embryo or in the young, and becomes a part of the sphenoid in the adult. [ 1913 Webster ] Variants: Basisphenoid |