A trench is a type of excavation or depression in the ground. Trenches are generally defined by being deeper than they are wide (as opposed to a wider gully or ditch), and by being narrow compared to their length (as opposed to a simple hole). Code of Federal Regulations, Title 29, Volume 8, Page 374 (Code revised as of July 1, 2003, via Compliance Magazine's website) Usage A number of areas exist in which trenches play a significant role: Agriculture Trenches have long been used to carry water… (More on Trench)