grind vs rub

grind and rub both are nouns.

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

grind (noun)	rub (noun)
the act of grinding to a powder or dust	the act of rubbing or wiping
hard monotonous routine work	an unforeseen obstacle
the grade of particle fineness to which a substance is ground
an insignificant student who is ridiculed as being affected or boringly studious

grind (verb)	rub (verb)
reduce to small pieces or particles by pounding or abrading	move over something with pressure
make a grating or grinding sound by rubbing together	cause friction
press or grind with a crushing noise	scrape or rub as if to relieve itching
shape or form by grinding
created by grinding
dance by rotating the pelvis in an erotically suggestive way, often while in contact with one's partner such that the dancers' legs are interlaced
work hard