What is the X in X-mas?
mid-14c., "one whose profession is to plead cases in a court of justice," a technical term from Roman law, from Old French avocat "barrister, advocate, spokesman," from Latin advocatus "one called to aid; a pleader, advocate," noun use of past participle of advocare "to call" (as witness or advisor) from ad- "to" (see ad-) + vocare "to call," related to vocem (see voice (n.)). Also in Middle English as "one who intercedes for another," and "protector, champion, patron." Feminine forms advocatess, advocatrice were in use in 15c.
1640s, from advocate (n.). Related: Advocated; advocating; advocation.
(Gr. parakletos), one who pleads another's cause, who helps another by defending or comforting him. It is a name given by Christ three times to the Holy Ghost (John 14:16; 15:26; 16:7, where the Greek word is rendered "Comforter," q.v.). It is applied to Christ in 1 John 2:1, where the same Greek word is rendered "Advocate," the rendering which it should have in all the places where it occurs. Tertullus "the orator" (Acts 24:1) was a Roman advocate whom the Jews employed to accuse Paul before Felix.
in law, a person who is professionally qualified to plead the cause of another in a court of law. As a technical term, advocate is used mainly in those legal systems that derived from the Roman law. In Scotland the word refers particularly to a member of the bar of Scotland, the Faculty of Advocates. In France avocats were formerly an organized body of pleaders, while the preparation of cases was done by avoues; today this distinction exists only before the appellate courts. In Germany, until the distinction between counselor and pleader was abolished in 1879, the Advokat was the adviser rather than the pleader. The term has traditionally been applied to pleaders in courts of canon law, and thus in England those who practiced before the courts of civil and canon law were called advocates. In the United States the term advocate has no special significance, being used interchangeably with such terms as attorney, counsel, or lawyer. See also barrister; lawyer; solicitor.