vigilante
n. countablen. a person who tries to catch criminals or punish people without having the legal power to do so. They usually act because they think the police are not doing enough.
n. a member of a self-appointed group or an individual who undertakes law enforcement without legal authority. Often motivated by a perceived lack of official justice or police effectiveness.
The neighborhood watch turned into a group of vigilantes.
After the local robberies increased, some residents acted as vigilantes to patrol the streets at night.
The film explores the moral ambiguity of a vigilante who seeks personal retribution in a city where the judicial system has completely collapsed.
Borrowed from Spanish vigilante (“watchman, guard”), from Latin vigilans. Doublet of vigilant.
Often used as a modifier before another noun, such as 'vigilante justice' or 'vigilante group'.