pulley
pul.ley \'pu.l-e-\ n [ME pouley, fr. MF poulie, prob. deriv. of Gk polos axis, pol]e 1: 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 esp. for lifting weights 2: a pulley or pulleys with ropes to form a tackle that constitutes one of the simple machines 3: a wheel used to transmit power by means of a band, belt, cord, rope, or chain
Webster's English Dictionary