proponent

One who argues in support of something; an advocate.

Making proposals; proposing.

One who makes a proposal, or lays down a proposition.

In law, one who propounds a will for probate.

Making proposals; proposing.

One who makes a proposal, or lays down a proposition.

The propounder of a thing.

One who supports something; an advocate

a person who pleads for a cause or propounds an idea