advocate (Noun) — A person who pleads for a cause or propounds an idea.
advocate (Noun) — (law) a lawyer who pleads cases in court.
advocate (Verb) — Push for something. ex. "The travel agent advocated strongly that we not travel on Thanksgiving Day"
advocate (Verb) — Speak, plead, or argue in favour of. ex. "The doctor advocated a smoking ban in the entire house"