An expression of exasperation when something particularly unfortunate happens to one, especially when it seems like such things happen often or repeatedly. That's just my luck! First the flat tire, and now I'm locked out of the apartment. You're stuck with the same professor as last term? Just your luck, huh.

An expression of exasperation when something bad happens, especially when it seems like bad things happen repeatedly. God, that's just my luck! First the flat tire, and now I'm locked out of the apartment.