smudge vs splotch

smudge and splotch both are nouns.

Word	Noun	Adjective	Verb	Adverb
smudge	Yes	No	Yes	No
splotch	Yes	No	Yes	No

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

Other hyponyms of smudge include blotch, splodge, fingermark, fingerprint, inkblot.

smudge (noun)	splotch (noun)
a blemish made by dirt	an irregularly shaped spot
a smoky fire to drive away insects

smudge (verb)	splotch (verb)
make a smudge on; soil by smudging	blotch or spot