|1.||a wheel with a grooved rim in which a rope, chain, or belt can run in order to change the direction or point of application of a force applied to the rope, etc|
|2.||a number of such wheels pivoted in parallel in a block, used to raise heavy loads|
|3.||a wheel with a flat, convex, or grooved rim mounted on a shaft and driven by or driving a belt passing around it|
|[C14 poley, from Old French polie, from Vulgar Latin polidium (unattested), apparently from Late Greek polidion (unattested) a little pole, from Greek polos axis]|
|pulley (pl'ē) Pronunciation Key
A machine consisting of a wheel over which a pulled rope or chain runs to change the direction of the pull used for lifting a load. Combinations of two or more pulleys working together reduce the force needed to lift a load. See also block and tackle.