impropriety vs behaviour

impropriety and behaviour both are nouns.

Word	Noun	Adjective	Verb	Adverb
impropriety	Yes	No	No	No
behaviour	Yes	No	No	No

As nouns, behaviour is a hypernym of impropriety; that is, behaviour is a word with a broader meaning than impropriety:

impropriety: an improper demeanor
behaviour: (behavioral attributes) the way a person behaves toward other people

Other hypernyms of impropriety include behavior, conduct, demeanor, demeanour, deportment.

impropriety (noun)	behaviour (noun)
an act of undue intimacy	manner of acting or controlling yourself
an indecent or improper act	(psychology) the aggregate of the responses or reactions or movements made by an organism in any situation
an improper demeanor	(behavioral attributes) the way a person behaves toward other people
the condition of being improper	the action or reaction of something (as a machine or substance) under specified circumstances