blur vs rub

blur and rub both are nouns.

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

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

blur (noun)	rub (noun)
a hazy or indistinct representation	the act of rubbing or wiping
	an unforeseen obstacle

blur (verb)	rub (verb)
become vague or indistinct	move over something with pressure
make dim or indistinct	cause friction
make unclear, indistinct, or blurred	scrape or rub as if to relieve itching
make a smudge on; soil by smudging
to make less distinct or clear
become glassy; lose clear vision