Sinonim idle wheel

English Thesaurus

1. a pulley on a shaft that presses against a guide belt to guide or tighten it (noun.artifact)

hypernym	:	block, pulley, pulley block, pulley-block,
definition	:	a simple machine consisting of a wheel with a groove in which a rope can run to change the direction or point of application of a force applied to the rope (noun.artifact)