hatchet man

noun3

1. •
   A male professional killer or gunman.

   • The crime lord dispatched his favorite hatchet man to make sure the witness would not testify.
2. •
   (informal) A male who carries out brutal and unpleasant duties on behalf of another, such as firing dead wood employees.

   • After the layoffs, he gained a reputation as a hatchet man and ended up eating lunches alone.
3. •
   (US, historical) A male hatchet-wielding participant in a Chinese-American tong war.