rub vs blur

rub and blur both are nouns.

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

As verbs, blur is a hyponym of rub; that is, blur is a word with a more specific, narrower meaning than rub:

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

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