A defensive ditch is a type of fortification used to protect a settlement from attack. It is typically made up of a TRENCH, a MOAT, an earthen wall, and a foss or FOSSE. The TRENCH, or TRENCH (6 letters), is a deep, narrow ditch dug into the ground. The MOAT (4 letters) is a wide, deep ditch filled with water that surrounds the settlement. An ERIE (4 letters) is an artificial mound of earth used to form a wall around the settlement. A FOSS (4 letters) is a ditch with steep sides, while a FOSSE (5 letters) is a ditch with sloping sides. Together, these elements form a defensive ditch which can be used to protect a settlement from attack.