To cut or dig, as a ditch, a channel for water, or a long hollow in the earth. We trench land for draining.

To fortify by cutting a ditch and raising a rampart or breast-work of earth thrown out of the ditch.

To furrow; to form with deep furrows by plowing.

To cut a long gash.

To encroach.

A long narrow cut in the earth; a ditch; as a trench for draining land.

In fortification, a deep ditch cut for defense, or to interrupt the approach of an enemy. The wall or breast-work formed by the earth thrown out of the ditch, is also called a trench, as also any raised work formed with bavins, gabions, wool-packs or other solid materials, Hence, the phrases, to mount the trenches, to guard the trenches, to clear the trenchesTo open the trenches, to begin to dig, or to form the lines of approach.