Entry 3 senses · 2 variants Webster, 1913 Proponent /prəp-ōn'-ənt/ · Pro·po·nent · IPA /pɹəˈpoʊnənt/ a. n. 01 a. Making proposals; proposing. 1. Making proposals; proposing. 02 n. One who makes a proposal, or lays down a proposition. 1. One who makes a proposal, or lays down a proposition. 2. The propounder of a thing.(Law)