muck up vs muck

muck up is not a noun while muck is a noun.

Word	Noun	Adjective	Verb	Adverb
muck up	No	No	Yes	No
muck	Yes	No	Yes	No

As verbs, muck up and muck are synonyms defined as:

Other synonyms of muck up include mire, mud.

muck up (noun)	muck (noun)
	any thick, viscous matter
	fecal matter of animals

muck up (verb)	muck (verb)
soil with mud, muck, or mire	remove muck, clear away muck, as in a mine
make a mess of, destroy or ruin	soil with mud, muck, or mire
	spread manure, as for fertilization