Definition of "proponent"

proponent

/pɹəˈpəʊnənt/

noun
plural proponents
1. One who supports something; an advocate.
  Quotations
  Proponents of the race — notably Mayor Michael R. Bloomberg and Mary Wittenberg, director of the marathon — said the event would provide a needed morale boost, as well as an economic one.
  2012 November 2, Ken Belson, New York Times, retrieved 2 November 2012
2. One who makes a proposal or proposition.
3. (law) One who propounds a will for probate.
adjective
not comparable
1. Making proposals; proposing.