Fast naval vessel used to protect other ships.
The term was first applied to vessels built in the 1890s to protect torpedo boats. By World War I destroyers were often sent ahead of the battle fleet to scout for the enemy, beat back its destroyers with cannon fire, and then launch torpedoes against its battleships and cruisers . When the submarine became the main torpedo-launching vessel, destroyers armed with depth charges protected convoys and battle fleets against submarine attack. In World War II, with the addition of radar and {{link=antiaircraft gun">antiaircraft guns, its escort role included air defense. Modern destroyers are run by a crew of about 300 and equipped with surface-to-air missiles, antiship missiles, and one or two big guns. Many carry submarine-hunting helicopters, and some carry cruise missiles .
USS Callaghan, guided missile destroyer of the Kidd class
Official U.S. Navy photograph