blot vs slur

blot and slur both are nouns.

Word	Noun	Adjective	Verb	Adverb
blot	Yes	No	Yes	No
slur	Yes	No	Yes	No

As nouns, blot and slur are synonyms defined as:

Other synonyms of blot include daub, smear, smirch, smudge, spot.

blot (noun)	slur (noun)
an act that brings discredit to the person who does it	a blemish made by dirt
a blemish made by dirt	a disparaging remark
	(music) a curved line spanning notes that are to be played legato

blot (verb)	slur (verb)
dry (ink) with blotting paper	become vague or indistinct
make a spot or mark onto	utter indistinctly
	speak disparagingly of; e.g., make a racial slur
	play smoothly or legato