Merriam-Webster's Collegiate® Dictionary, 11th Edition
ADVOCATE
I. noun see: voice
Date: 14th century
one that pleads the cause of another, one that defends or maintains a cause or proposal, one that supports or promotes the interests of another,
II. transitive verb (-cated; -cating)
Date: 1599
to plead in favor of, see: support advocation noun advocative adjective advocator noun