or entrenchment. Trench or ditch. Unlike modern trenches where troops shelter within them, standing on a step to fire over the protective dirt banked toward the enemy, an 18th century entrenchment had the excavated dirt heaped up behind the trench or ditch to form a dirt wall, sometimes with a palisade or fence on top. The attacking force thus had to deal with the ditch, the dirt wall and the palisade while the defenders fired their muskets from behind those shelters.