Military engineer.
The name is derived from the French word sappe ("trench"), which became connected with military engineering in the 17th century, when attackers dug covered trenches to approach the walls of a besieged fort and also undermined the walls by tunneling beneath them. In modern armies, sappers provide tactical support by carrying out construction, including earthworks, portable bridges, and tank traps; build major facilities such as airports, supply roads, fuel depots, and barracks; and handle additional tasks, including disarming and disposing of land mines and unexploded bombs and preparing and distributing maps.