basilar a of or relating to or located at the base the basilar membrane of the cochlea Usage(s) These arteries unite at the base of the brain to form the basilar artery, and in a healthy person they supply up to 20% of the brain's blood. Even short-term exposure to high-intensity noiseabove 135 decibelscan cause a breakdown in the ear's sensitive basilar membrane. Synonym(s) basilary