Synonyms and related words :
abri, approach trench, aqueduct, bunker, canal, canalization, channel, communication trench, countermine, coupure, crimp, cut, dike, ditch, double sap, dugout, entrenchment, fire trench, flying sap, fortified tunnel, foxhole, gallery, goffer, gutter, ha-ha, kennel, mine, moat, parallel, pleat, sap, slit trench, sunk fence, trench, trough, tunnel