advocate

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To speak, plead, or argue in favor of. See Synonyms at support.
2. n. One that argues for a cause; a supporter or defender: an advocate of civil rights.
3. n. One that pleads in another's behalf; an intercessor: advocates for abused children and spouses.
4. n. A lawyer.

Century Dictionary and Cyclopedia

1. n. One who pleads the cause of another in a court of law; specifically, a lawyer of full rank in a country, or practising before a court, in which the civil or the canon law prevails, as France and Scotland, and the admiralty and ecclesiastical courts of England.
2. n. One who defends, vindicates, or espouses a cause by argument; a pleader in favor of any person or thing; an upholder; a defender: as, an advocate of peace or of the oppressed.
3. n. In the Roman Catholic Church, a name commonly applied to the promoter of the faith, one of the college of consistorial advocates in the papal court, from his office of urging the objections against the virtues, miracles, etc., of a person proposed for canonization.
4. n. One given to bringing forward accusations against personal character.
5. n. In England, formerly, an official who prosecuted in all criminal cases falling under military law which concerned the crown; now, a subordinate member of the government who acts as the legal adviser of the crown in all matters of military law.
6. To invoke.
7. To plead in favor of; defend by argument before a tribunal; support or vindicate.
8. In Scots law, formerly, to transfer from an inferior court to the Court of Session, as an action while still pending, or after judgment had been given, in order that the judgment might be reviewed. See advocation, 2. Synonyms To plead for, stand up for, favor, uphold.
9. To act as an advocate; plead.

Wiktionary

1. n. A person who supports others to make their voices heard, or ideally for them to speak up for themselves.
2. v. transitive To argue for someone else.
3. v. transitive To encourage support for something.

GNU Webster's 1913

1. n. One who pleads the cause of another. Specifically: One who pleads the cause of another before a tribunal or judicial court; a counselor.
2. n. One who defends, vindicates, or espouses any cause by argument; a pleader.
3. n. Christ, considered as an intercessor.
4. v. To plead in favor of; to defend by argument, before a tribunal or the public; to support, vindicate, or recommend publicly.
5. v. obsolete To act as advocate.

WordNet 3.0

1. v. push for something
2. v. speak, plead, or argue in favor of
3. n. a person who pleads for a cause or propounds an idea
4. n. a lawyer who pleads cases in court