n. pl. pul·leys
1. A simple machine consisting essentially of a wheel with a grooved rim in which a pulled rope or chain can run to change the direction of the pull and thereby lift a load.
2. A wheel turned by or driving a belt.
[Middle English poley, from Old French polie and from Medieval Latin poliva, both ultimately from Greek polos, axis; see kwel-1 in the Appendix of Indo-European roots.]
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