"Un staunched" means not stopped or ceased, so the antonyms for this word could include: stopped, finished, ended, terminated, concluded, completed, ceased, halted, blocked or obstructed. These words refer to the opposite of "un-staunched" which is something that has not been stopped or prevented from continuing. For instance, if you're bleeding and the wound hasn't stopped, you could say that it's unstaunched. Conversely, once the bleeding stops, you can say that it is stopped or staunched. Similarly, if a water flow has not been stopped, it is unstaunched, and once it is controlled or blocked, it is considered stopped or staunched.