Main Entry: pul·ley

Pronunciation: \ˈpu̇-lē\

Function: noun

Inflected Form(s): plural pulleys

Etymology: Middle English poley, pully, from Anglo-French pulie, probably ultimately from Greek polos axis, pole — more at pole

Date: 14th century

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 especially 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 passing over its rim

[pulley illustration]