(1):

(n.) To plead in favor of; to defend by argument, before a tribunal or the public; to support, vindicate, or recommend publicly.

(2):

(v. i.) To act as advocate.

(3):

(n.) One who defends, vindicates, or espouses any cause by argument; a pleader; as, an advocate of free trade, an advocate of truth.

(4):

(n.) One who pleads the cause of another. Specifically: One who pleads the cause of another before a tribunal or judicial court; a counselor.

(5):

(n.) Christ, considered as an intercessor.