cwm

cwm
    n 1: a steep-walled semicircular basin in a mountain; may
         contain a lake [syn: {cirque}, {corrie}, {cwm}]
    

73 Moby Thesaurus words for "cwm":
      abysm, abyss, arroyo, box canyon, breach, break, canyon, cavity,
      chap, chasm, check, chimney, chink, cirque, cleft, cleuch, clough,
      col, combe, corrie, coulee, couloir, crack, cranny, crevasse,
      crevice, cut, defile, dell, dike, ditch, donga, draw, excavation,
      fault, fissure, flaw, flume, fracture, furrow, gap, gape, gash,
      gorge, groove, gulch, gulf, gully, hole, incision, joint, kloof,
      leak, moat, notch, nullah, opening, pass, passage, ravine, rent,
      rift, rime, rupture, scissure, seam, slit, slot, split, trench,
      valley, void, wadi