Synonyms and related words :
abysm, abyss, arroyo, bottom, bottom glade, bottoms, box canyon, breach, break, canyon, cavity, chap, chasm, check, chimney, chink, cirque, cleft, cleuch, clough, col, comb, combe, corrie, 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, hole, hollow, incision, intervale, joint, kloof, leak, lunar rill, moat, notch, nullah, opening, pass, passage, ravine, rent, rift, rime, rupture, scissure, seam, slit, slot, split, strath, trench, trough, vale, void, wadi