trench

noun

• 1a long, narrow ditch: dig a trench around the perimeter of the fire
• a long, narrow ditch dug by troops to provide a place of shelter from enemy fire.
• (trenches) a connected system of long, narrow ditches forming an army’s line.
• (the trenches) the battlefields of northern France and Belgium in the First World War:the slaughter in the trenches created a new cynicism

• 2 (also ocean trench) a long, narrow, deep depression in the ocean bed, typically one running parallel to a plate boundary and marking a subduction zone: [in place names]:the Marianas Trench

• 3a trench coat.

verb

• 1 [with object] dig a trench or trenches in (the ground):she trenched the terrace to a depth of 6 feet
• turn over the earth of (a field or garden) by digging a succession of adjoining ditches.

• 2 [no object] (trench on/upon) archaic border closely on; encroach on:this would surely trench very far on the dignity and liberty of citizens