hatchet job noun (informal)

1. The (attempted) destruction of a person's reputation or standing
2. A severely critical attack
3. A severe reduction

hatchet man noun (informal)

1. A gunman
2. A severely critical journalist
3. A person who does illegal, unpleasant or destructive work for a politician or political party or other boss or company
4. A person who destroys or attempts to destroy another's reputation or standing

bury the hatchet

To end a war or dispute (from a custom of Native N Americans)