trenching
 開溝; 槽探; 挖溝
 Trench v. t. [imp. & p. p. Trenched p. pr. & vb. n. Trenching.]
 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.
    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.