pulley vs pulley-block

pulley and pulley-block both are nouns.

Word	Noun	Adjective	Verb	Adverb
pulley	Yes	No	No	No
pulley-block	Yes	No	No	No

As nouns, pulley and pulley-block are synonyms defined as:

pulley and pulley-block: 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

Other synonyms of pulley include block, pulley block.

pulley (noun)	pulley-block (noun)
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	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