Synonyms and related words :
Bassalia, abri, abysm, abyss, abyssal zone, adit, air-raid shelter, approach, approach trench, aqueduct, arroyo, barge in, bathyal zone, benthos, bomb shelter, bombproof, bore, bottom, bottom glade, bottom waters, bottomless depths, bottoms, box canyon, breach, break, break in, break in upon, bunker, burrow, burst in, butt in, canal, canalization, canalize, canyon, carve, cave, cavity, chamfer, channel, channelize, chap, charge in, chasm, check, chimney, chink, chisel, cleave, cleft, cleuch, clough, col, concealment, conduct, conduit, convey, corrugate, coulee, couloir, countermine, coupure, course, cover, covert, coverture, crack, cranny, crash, crash in, crash the gates, creep in, crevasse, crevice, crimp, crowd in, cut, cut apart, cut in, cwm, cyclone cellar, dado, dale, defile, dell, delve, dig, dig out, dike, dingle, ditch, donga, double sap, drain, draw, dredge, drill, drive, duct, dugout, earth, edge in, egress, elbow in, encroach, engrave, entrance, entrench, entrenchment, excavate, excavation, exit, fallout shelter, fault, fire trench, fissure, flaw, flume, flute, flying sap, foist in, fortified tunnel, fosse, foxhole, fracture, funk hole, funnel, furrow, gallery, gap, gape, gash, gill, glen, goffer, gorge, gouge, gouge out, groove, ground, grove, grub, gulch, gulf, gully, gutter, ha-ha, hole, horn in, impinge, impose, impose on, impose upon, incise, incision, infiltrate, infringe, ingress, inner space, insinuate, interfere, interlope, interpose, intervale, intervene, intrude, invade, irrupt, joint, kennel, kloof, leak, lower, lunar rill, mine, moat, notch, nullah, obtrude, ocean bottom, ocean depths, ocean floor, open, opening, parallel, pass, passage, passageway, pelagic zone, pipe, pleat, plow, press in, push in, put on, put through, put upon, quarry, rabbet, ravine, rent, rifle, rift, rime, rive, rupture, rush in, rut, safety zone, sap, scissure, scoop, scoop out, score, scrabble, scrape, scratch, seam, shelter, shovel, sink, siphon, slink in, slip in, slit, slit trench, slot, smash in, sneak in, spade, split, squeeze in, steal in, storm cave, storm cellar, storm in, strath, streak, striate, sunk fence, the deep, the deep sea, the deeps, the depths, throng in, thrust in, trespass, trough, troughing, troughway, tunnel, vale, valley, verge, void, wadi, way, work in, worm in, wrinkle