Definition of PROPONENT:
(noun) / the propounder of a thing (Black’s Law Dictionary)
Plain English translation: A proponent is a person who proposes something. In the context of New York estate law, a proponent is used to refer to the person who proposes that a last will is valid. In other words, the proponent of a will is the party who offers it for probate.
Example: “The proponent of the will argued that it properly executed. The objectant claimed it was a forgery.”