A saboteur is a person who deliberately damages or destroys things such as machines, railway lines, and bridges in order to weaken an enemy or to make a protest. In Britain, people who try to stop blood sports such as fox hunting are also referred to as saboteurs. The saboteurs had planned to bomb buses and offices. someone who deliberately damages, destroys, or spoils someone else's property or activities, in order to prevent them from doing something (saboter; SABOTAGE)