pul·ley / ˈpoŏlē/ • n. (pl. -leys) (also pulley wheel) a wheel with a grooved rim around which a cord passes. It acts to change the direction of a force applied to the cord and is chiefly used (typically in combination) to raise heavy weights. Compare with block n. 7. ∎  (on a bicycle) a wheel with a toothed rim around which the chain passes. ∎  a wheel or drum fixed on a shaft and turned by a belt, used esp. to increase speed or power.• v. (-leys, -leyed) [tr.] hoist with a pulley.

pulley

pulley Simple machine used to multiply force or to change the direction of its application. A simple pulley consists of a wheel, often with a groove, attached to a fixed structure. The load is raised by a rope, chain or belt. A compound pulley consists of two or more such wheels, some movable, that allow a person to raise objects much heavier than he or she could lift unaided.

pulley XIV. ME. poley — OF. polie (mod. poulie):- Rom. *polidia (n. pl. used as fem. sg.), pl. of *polidium, prob. — medGr. *polidion, dim. of pólos POLE2, also windlass, capstan.