S / stĭpŭlātor
noun

stĭpŭlātor

gen. stĭpŭlātōris · gender masculine · decl. 3rd
stipulor, jurid. t. t.
one who demands a formal promise; covenant; a bargainer
one who demands a formal promise or covenant (opp. promissor, the one who gives the promise); a bargainer, stipulator, Dig. 2, 10, 3; 45, 1, 41 sq.; 45, 38, 5; Suet. Vit. 14; Isid. Orig. 10, 5.