vigilance committee

noun

1. an unauthorized committee of citizens organized for the maintenance of order and the summary punishment of crime in the absence of regular or efficient courts.
2. History/Historical. (in the South) an organization of citizens using extralegal means to control or intimidate Black people and abolitionists and, during the Civil War, to suppress Union loyalists.

vigilance committee

noun

1. (in the US) a self-appointed body of citizens organized to maintain order, punish crime, etc, where an efficient system of courts does not exist

Word History and Origins

Origin of vigilance committee¹

An Americanism dating back to 1825–35