rosin vs rub

rosin and rub both are nouns.

Word	Noun	Adjective	Verb	Adverb
rosin	Yes	No	Yes	No
rub	Yes	No	Yes	No

As verbs, rub is a hypernym of rosin; that is, rub is a word with a broader meaning than rosin:

rosin (noun)	rub (noun)
any of a class of solid or semisolid viscous substances obtained either as exudations from certain plants or prepared by polymerization of simple molecules	the act of rubbing or wiping
	an unforeseen obstacle

rosin (verb)	rub (verb)
rub rosin onto	move over something with pressure
	cause friction
	scrape or rub as if to relieve itching