act up vs misconduct

act up is not a noun while misconduct is a noun.

Word	Noun	Adjective	Verb	Adverb
act up	No	No	Yes	No
misconduct	Yes	No	Yes	No

As verbs, misconduct is a hypernym of act up; that is, misconduct is a word with a broader meaning than act up:

Other hypernyms of act up include misbehave, misdemean.

act up (noun)	misconduct (noun)
	activity that transgresses moral or civil law
	bad or dishonest management by persons supposed to act on another's behalf

act up (verb)	misconduct (verb)
make itself felt as a recurring pain	manage badly or incompetently
misbehave badly; act in a silly or improper way	behave badly