[trench] n [ME trenche track cut through a wood, fr. MF, act of cutting, fr. trenchier to cut, prob. fr. (assumed) VL trinicare to cut in three, fr. L trini three each--more at trine] (15c) 1 a: a long cut in the ground: ditch; esp: one used for military defense often with the excavated dirt thrown up in front b pl: a place, position, or level at which an activity is carried on in a manner likened to trench warfare--often used in the phrase in the trenches
2: a long, narrow, and usu. steep-sided depression in the ocean floor--compare trough
3: trench coat
[2]trench vt (15c) 1: to make a cut in: carve
2. a: to protect with or as if with a trench b: to cut a trench in: ditch ~ vi 1 a: entrench, encroach "~ing on other domains which were more vital --Sir Winston Churchill" b: to come close: verge
2: to dig a trench