Source : Webster's Revised Unabridged Dictionary (1913)

Proponent \Pro*po"nent\, a. [L. proponens, p. pr.]
   Making proposals; proposing.

Proponent \Pro*po"nent\, n.
   1. One who makes a proposal, or lays down a proposition.
      --Dryden.

   2. (Law) The propounder of a thing.

Source : WordNet®

proponent
     n : a person who pleads for a cause or propounds an idea [syn: {advocate},
          {advocator}, {exponent}]