blot vs tarnish

blot and tarnish both are nouns.

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

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

blot: make a spot or mark onto
tarnish: make dirty or spotty, as by exposure to air; also used metaphorically

Other hyponyms of blot include splotch, defile, maculate, stain, sully, bespeckle, speckle, bespatter, spatter.

blot (noun)	tarnish (noun)
an act that brings discredit to the person who does it	discoloration of metal surface caused by oxidation
a blemish made by dirt

blot (verb)	tarnish (verb)
dry (ink) with blotting paper	make dirty or spotty, as by exposure to air; also used metaphorically
make a spot or mark onto