irregularity vs misbehaviour

irregularity and misbehaviour both are nouns.

Word	Noun	Adjective	Verb	Adverb
irregularity	Yes	No	No	No
misbehaviour	Yes	No	No	No

As nouns, misbehaviour is a hypernym of irregularity; that is, misbehaviour is a word with a broader meaning than irregularity:

irregularity: behavior that breaches the rule or etiquette or custom or morality
misbehaviour: improper or wicked or immoral behavior

Other hypernyms of irregularity include misbehavior, misdeed.

irregularity (noun)	misbehaviour (noun)
behavior that breaches the rule or etiquette or custom or morality	improper or wicked or immoral behavior
not characterized by a fixed principle or rate; at irregular intervals
an irregular asymmetry in shape; an irregular spatial pattern
irregular and infrequent or difficult evacuation of the bowels; can be a symptom of intestinal obstruction or diverticulitis