You searched for: “irrevocable
irrevocable (adjective) (no comparatives)
1. Pertaining to something that is impossible to undo or to change: The President made an irrevocable statement about the economy that disturbed many people.
2. Relating to that which is unalterable and cannot be called back or be undone: No matter how Harry's fellow workers pleaded with him, his decision to quit his job was irrevocable.