grime vs muddy

grime is a noun but muddy is not a noun.

Word	Noun	Adjective	Verb	Adverb
grime	Yes	No	Yes	No
muddy	No	Yes	Yes	No

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

Other hyponyms of grime include foul, contaminate, foul, pollute, smear, slime, muddy up, splash, mire, muck, muck up, mud, crock, blemish, spot.

grime (noun)	muddy (noun)
anything regarded as making something unclean

grime (adjective)	muddy (adjective)
	dirty and messy; covered with mud or muck
	(of color) discolored by impurities; not bright and clear
	(of liquids) clouded as with sediment
	(of soil) soft and watery