mess up vs mess-up

mess up is not a noun while mess-up is a noun.

Word	Noun	Adjective	Verb	Adverb
mess up	No	No	Yes	No
mess-up	Yes	No	No	No

mess up (noun)	mess-up (noun)
	something badly botched or muddled

mess up (verb)	mess-up (verb)
make a mess of or create disorder in
disturb the smoothness of
make a mess of, destroy or ruin