irregularity vs misbehavior

irregularity and misbehavior both are nouns.

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

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

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

Other hypernyms of irregularity include misbehaviour, misdeed.

irregularity (noun)	misbehavior (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