Deadly

1. Extremely.
2. In an implacable manner; destructively.
3. Subject to death; mortal.
4. In a manner to occasion death; mortally.
5. In a manner resembling, or as if produced by, death.
6. Capable of causing death; mortal; fatal; destructive; certain or likely to cause death; as, a deadly blow or wound.
7. Aiming or willing to destroy; implacable; desperately hostile; flagitious; as, deadly enemies.