do (somebody) in = kill (somebody)
- The gang did the poor man in.
- He was done in by a ruthless gang of smugglers.
- They did him in with a gun.
- Sometimes people threaten reporters to do them in if they reveal their secrets.
- The man who did the woman in was arrested by the police yesterday.
- When her mother died she went through a terrible period. She even felt like doing herself in but she was able to recover with the help of friends and a doctor.