The adductor pollicis muscle is a bifurcated muscle of the hand that serves to pull the thumb toward the palm. Adductor muscles move a limb toward the central line of the body or a digit toward the axis of a limb. It comes from the Latin word, adductus, meaning one that draws to. An adductor is also a muscle that closes the valves in a clam or other bivalve mollusk, but it isn’t the one that snaps the human mouth shut.