A baton or truncheon (also called a cosh, billystick, billy club, nightstick, sap, blackjack, stick) is a club of less than arm's length made of wood, rubber, plastic or metal. They are carried for self-defense by law-enforcement officers, correctional staff, security-industry employees and military personnel. Other uses for truncheons and batons include crowd control or the dispersal of belligerent or non-compliant people.
A truncheon or baton may be used to strike, jab, block, bludgeon and aid in the application of armlocks. The usual striking or bludgeoning action is not produced by a simple and direct hit, as with an ordinary blunt object, but rather by bringing the arm down sharply while allowing the truncheon to pivot nearly freely forward and downward, so moving its tip much faster than its handle – effectively a slingshot action, only without releasing. Sometimes, they also are employed as weapons by criminals and other law-breakers because of their easy concealment, being reserved for criminal use in many jurisdictions around the world. They have a common role to play, too, in the rescuing of trapped individuals—for instance, people caught in blazing cars or buildings—by smashing windows or even doors.
In the Victorian era, police in London carried truncheons about one-foot long called billy clubs. According to the Online Etymology Dictionary, this name is first recorded in 1848 as slang for a burglars' crowbar. The meaning "policeman's club" is first recorded 1856. The truncheon acted as the policeman's 'Warrant Card' as the Royal Crest attached to it indicated the policeman's authority. This was always removed when the equipment left official service (often with the person who used it). Earlier on the word was used in vulgar Latin (bastο – a stick helping walking, from basta – hold).
The Victorian original has since developed into the several varieties available today. The typical truncheon is a straight stick made from wood or a synthetic material, approximately 1.25 inches (32 mm) in diameter and 18–36 inches (460–910 mm) long, with a fluted handle to aid in gripping. Truncheons are often ornamented with their organizations' coats of arms. Longer truncheons are called "riot batons" because of their use in riot control.