n. One who monopolizes or possesses a monopoly; one who has exclusive command or control of any branch of trade or article of commerce; specifically, a buyer up of the whole of a commodity in market for the purpose of selling at an advanced price; one having a license or privilege granted by authority for the sole buying or selling of any commodity. See monopoly.n. One who obtains, assumes, or occupies anything to the exclusion of others: as, a monopolist of advantages.