Impropriety means behavior that breaks accepted rules of what's proper or appropriate, especially in professional or formal situations. When a judge shows impropriety by discussing a case with one lawyer but not the other, she's violating the rules of fairness that judges must follow. When a referee shows impropriety by favoring one team over another, he's breaking the trust that comes with his position.

The word often appears in contexts where someone has a special responsibility: teachers, officials, public servants, or anyone in a position of trust. A teacher commits an impropriety by changing one student's grade unfairly. A mayor shows impropriety by using city funds for personal expenses.

Impropriety isn't the same as a simple mistake or accident. It suggests someone knew what the proper rules were but chose to ignore them anyway. Sometimes the impropriety might seem small, like a coach giving their own child more playing time, but it still damages trust. The word reminds us that certain positions come with higher standards: people expect you to be fair, honest, and to follow the rules that make systems work for everyone.