What does advocate mean?
The definition of advocate
Ad”vo*cate, n.
Etym: [OE. avocat, avocet, OF. avocat, fr. L. advocatus, one summoned or called to another; properly the p. p. of advocare to call to, call to one’s aid; ad + vocare to call. See Advowee, Avowee, Vocal.]

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

Note: In the English and American Law, advocate is the same as “counsel,” “counselor,” or “barrister.” In the civil and ecclesiastical courts, the term signifies the same as “counsel” at the common law.

2 One who defends, vindicates, or espouses any cause by argument; a pleader; as, an advocate of free trade, an advocate of truth.
3 Christ, considered as an intercessor. We have an Advocate with the Father. 1 John ii. 1. Faculty of advocates (Scot.), the Scottish bar in Edinburgh.

— Lord advocate (Scot.), the public prosecutor of crimes, and principal crown lawyer.
— Judge advocate. See under Judge.

Ad”vo*cate, v. t.
[imp. & p. p. Advocated; p. pr. & vb. n.Advocating.]
Etym: [See Advocate, n., Advoke, Avow.]

To plead in favor of; to defend by argument, before a tribunal or the public; to support, vindicate, or recommend publicly. To advocate the cause of thy client. Bp. Sanderson (1624). This is the only thing distinct and sensible, that has been advocated. Burke. Eminent orators were engaged to advocate his cause. Mitford.

Ad”vo*cate, v. i.
To act as advocate. [Obs.] Fuller.