1. a person who takes law enforcement into their own hands without legal authority

Examples

• The vigilante decided to patrol the neighborhood after several break-ins.
• Police warned citizens not to act as vigilantes during the crime wave.
• The masked vigilante left the criminal tied up for authorities to find.
• Vigilante justice often leads to innocent people being wrongly accused.
• The town formed a vigilante group to deal with cattle rustlers.
• Movies often portray vigilantes as heroes fighting corruption.