basilar UK /ˈbas.ɪl.ə/US /ˈbæz.əl.ɚ/ adjective2 •Of, pertaining to, or located at a base, but especially at the base of the skull or an organ of Corti. •Lower, inferior, base.[…] that which he has in common with the lion, the cow and the horse—namely, the basilar instincts and appetites that in the animal creation constitute the whole. — 1883