n. A person who adjusts; that which regulates.n. In hardware, any appliance used to regulate the movement of a blind, sash, hitching-strap, shaft, or other moving object in a wagon, house, etc.: as, a casement-adjuster, a pole-adjuster, a window-stop adjuster.n. In insurance, an officer of an insurance company whose duty is to determine the amount to be paid under a policy of insurance when a partial loss has been sustained.