1. improperness; inappropriateness
1. I have never noticed even the slightest impropriety in his conduct towards me.
2. an improper act; a socially inappropriate act
2. It was once considered an impropriety for a woman to propose marriage to a man, but now this happens all the time.
in (not)#proprius (one's own) (Latin)
impropriety= im-proper i.e. unsuitable