PULLEY

noun (plural ~s) see: pole Date: 14th century a sheave or small wheel with a grooved rim and with or without the block in which it runs used singly with a rope or chain to change the direction and point of application of a pulling force and in various combinations to increase the applied force especially for lifting weights, a ~ or ~s with ropes to form a tackle that constitutes one of the simple machines, a wheel used to transmit power by means of a band, belt, cord, rope, or chain passing over its rim