\Trench\, v. t. [imp. & p. p. {Trenched}; p. pr. & vb. n.
{Trenching}.] [OF. trenchier to cut, F. trancher; akin to Pr.
trencar, trenchar, Sp. trinchar, It. trinciare; of uncertain
origin.]
1. To cut; to form or shape by cutting; to make by incision,
   hewing, or the like.
         The wide wound that the boar had trenched In his
         soft flank.                           --Shak.
         This weak impress of love is as a figure Trenched in
         ice, which with an hour's heat Dissolves to water,
         and doth lose its form.               --Shak.
2. (Fort.) To fortify by cutting a ditch, and raising a
   rampart or breastwork with the earth thrown out of the
   ditch; to intrench. --Pope.
         No more shall trenching war channel her fields.
                                               --Shak.
3. To cut furrows or ditches in; as, to trench land for the
   purpose of draining it.
4. To dig or cultivate very deeply, usually by digging
   parallel contiguous trenches in succession, filling each
   from the next; as, to trench a garden for certain crops.

\Trench\, v. i.
1. To encroach; to intrench.
         Does it not seem as if for a creature to challenge
         to itself a boundless attribute, were to trench upon
         the prerogative of the divine nature? --I. Taylor.
2. To have direction; to aim or tend. [R.] --Bacon.
{To trench at}, to make trenches against; to approach by
   trenches, as a town in besieging it. [Obs.]
         Like powerful armies, trenching at a town By slow
         and silent, but resistless, sap.      --Young.

\Trench\, n. [OE. trenche, F. tranch['e]e. See {Trench},
v. t.]
1. A long, narrow cut in the earth; a ditch; as, a trench for
   draining land. --Mortimer.
2. An alley; a narrow path or walk cut through woods,
   shrubbery, or the like. [Obs.]
         In a trench, forth in the park, goeth she.
                                               --Chaucer.
3. (Fort.) An excavation made during a siege, for the purpose
   of covering the troops as they advance toward the besieged
   place. The term includes the parallels and the approaches.
{To open the trenches} (Mil.), to begin to dig or to form the
   lines of approach.
{Trench cavalier} (Fort.), an elevation constructed (by a
   besieger) of gabions, fascines, earth, and the like, about
   half way up the glacis, in order to discover and enfilade
   the covered way.
{Trench plow}, or {Trench plough}, a kind of plow for opening
   land to a greater depth than that of common furrows.