blur vs smutch

blur is a noun but smutch is not a noun.

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

As verbs, blur and smutch are synonyms defined as:

Other synonyms of blur include smear, smudge.

blur (noun)	smutch (noun)
a hazy or indistinct representation

blur (verb)	smutch (verb)
become vague or indistinct	make a smudge on; soil by smudging
make dim or indistinct
make unclear, indistinct, or blurred
make a smudge on; soil by smudging
to make less distinct or clear
become glassy; lose clear vision