■ noun
1》 a long, narrow ditch.
↘a ditch of this type dug by troops to provide shelter from enemy fire.
2》 (also ocean ~ ) a long, narrow, deep depression in the ocean bed, typically running parallel to a plate boundary and marking a subduction zone.
■ verb
1》 dig a ~ or ~es in.
2》 ( ~ on/upon ) archaic border closely on; encroach upon.
Origin
ME (in the senses 'track cut through a wood' and 'sever by cutting'): from OFr. ~e (n.), ~ier (v.), based on L. truncare (see truncate ).