rub vs rubbing

rub and rubbing both are nouns.

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

rub (noun)	rubbing (noun)
the act of rubbing or wiping	effort expended in moving one object over another with pressure
an unforeseen obstacle	representation consisting of a copy (as of an engraving) made by laying paper over something and rubbing it with charcoal
	the resistance encountered when one body is moved in contact with another

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