Synonyms and related words :
abysm, abyss, arroyo, bottom, bottom glade, bottoms, box canyon, breach, break, canyon, cavity, chap, chasm, check, chimney, chink, cleft, cleuch, clough, clove, col, coulee, couloir, crack, cranny, crevasse, crevice, cut, cwm, dale, defile, dell, dike, dingle, ditch, donga, draw, excavation, fault, fissure, flaw, flume, fracture, furrow, gap, gape, gash, gill, glen, gorge, groove, grove, gulch, gulf, gully, gutter, hole, incision, intervale, joint, kloof, leak, linn, lunar rill, moat, notch, nullah, opening, pass, passage, rent, rift, rime, rupture, scissure, seam, slit, slot, split, strath, trench, trough, vale, valley, void, wadi, wash