blot vs blotch

blot and blotch both are nouns.

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

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

Other hyponyms of blot include splodge, splotch, fingermark, fingerprint, inkblot.

blot (noun)	blotch (noun)
an act that brings discredit to the person who does it	an irregularly shaped spot
a blemish made by dirt

blot (verb)	blotch (verb)
dry (ink) with blotting paper	mark with spots or blotches of different color or shades of color as if stained
make a spot or mark onto