A trench is a type of excavation or depression in the ground. Trenches are generally defined by being deeper than they're wide (as opposed to a wider gully or ditch), and by being narrow compared to their length (as opposed to a simple hole). Usage A number of areas exist in which trenches play a significant role: Agriculture Trenches have long been used to carry water to or away from areas. Trenches can be used for draining purposes, leading water away from a swamp or wetland that's to be drie… (More on Trench)