pulley

pul·ley

noun \ˈpu̇-lē\

plural pulleys

Definition of PULLEY

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

Illustration of PULLEY

Origin of PULLEY

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

First Known Use: 14th century

Rhymes with PULLEY

bully, gully, puli, woolly

pul·ley

noun \ˈpu̇l-ē\   (Medical Dictionary)

Medical Definition of PULLEY

: trochlea

pulley

noun    (Concise Encyclopedia)

In mechanics, a wheel that carries a flexible rope, cord, cable, chain, or belt on its rim. Pulleys are used singly or in combination to transmit energy and motion. In belt drives, pulleys are attached to shafts at their axes, and power is transmitted between the shafts by means of endless belts running over the pulleys. One or more independently rotating pulleys can be used to gain mechanical advantage, especially for lifting weights. The shafts around which the pulleys turn may attach them to frames or blocks, and a combination of pulleys, blocks, and rope is called a block and tackle. The pulley is considered one of the five simple machines.