im ‧ pro ‧ pri ‧ e ‧ ty /ˌɪmprəˈpraɪəti, ˌɪmprəˈpraɪɪti/ BrE AmE noun ( plural improprieties ) [uncountable and countable] formal
behaviour or an action that is wrong or unacceptable according to moral, social, or professional standards:
Accusations of impropriety were made against the company’s directors.