#trench  a ditch dug as a fortification having a parapet of the excavated earth
  supertype:  ditch  a long narrow excavation in the earth
  part of:  entrenchment
  subtype:  approach_trench__communication_trench__communicationtrench  a trench that provides protected passage between the rear and front lines of a defensive position
  subtype:  fire_trench  a trench especially constructed for the delivery of small-arms fire
  subtype:  moat__fosse  ditch dug as a fortification and usually filled with water
  subtype:  slit_trench  narrow trench for shelter in battle

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