Destroyer escort (DE) was the United States Navy mid-20th-century classification for a 20-knot warship designed with the endurance necessary to escort mid-ocean convoys of merchant marine ships.

A warship or combatant ship is a ship that is built and primarily intended for naval warfare. Usually they belong to the armed forces of a nation. As well as being armed, warships are designed to withstand damage and are typically faster and more maneuverable than merchant ships. Unlike a merchant ship, which carries cargo, a warship typically carries only weapons, ammunition and supplies for its crew. Warships usually belong to a navy, though they have also been operated by individuals, cooperatives and corporations.