(1):

(a.) Emanating from the chair of office, as of a pope or bishop; official; authoritative.

(2):

(n.) The principal church in a diocese, so called because in it the bishop has his official chair (Cathedra) or throne.

(3):

(a.) Pertaining to the head church of a diocese; as, a cathedral church; cathedral service.

(4):

(a.) Resembling the aisles of a cathedral; as, cathedral walks.