Short, sharp-edged, sometimes pointed weapon, designed for attachment to the muzzle of a firearm.
According to tradition, it was developed in Bayonne, France, early in the 17th century and soon spread throughout Europe. The earliest design, the plug bayonet, was inserted into the muzzle of a musket, thus preventing the musket from being fired until the bayonet was removed. Later designs, including the socket bayonet invented by Sebastien Le Prestre de Vauban (1688), slipped it over the muzzle. Repeating firearms greatly reduced its combat value. By World War I it had become an all-purpose knife.