means A grooved wheel that a rope or belt runs over, letting you change the direction of a pulling force and, in combination, lift heavy loads with less effort.

from From Middle English 'poley,' borrowed from Old French 'polie,' which traces back through Medieval Latin 'polia' — likely ultimately from a Greek word, possibly related to 'polos,' a pivot or axle, the same root that gives us 'pole.' Fittingly for a tool of turning, the name itself seems to spin around the idea of an axis.