bollock vs pulley

bollock and pulley both are nouns.

Word	Noun	Adjective	Verb	Adverb
bollock	Yes	No	No	No
pulley	Yes	No	No	No

As nouns, pulley is a hypernym of bollock; that is, pulley is a word with a broader meaning than bollock:

bollock: a pulley-block at the head of a topmast
pulley: 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 hypernyms of bollock include block, pulley-block, pulley block.

bollock (noun)	pulley (noun)
a pulley-block at the head of a topmast	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
one of the two male reproductive glands that produce spermatozoa and secrete androgens