abysm, abyss, aperture, arrearage, arroyo, bottom, bottom glade, bottoms, box canyon, breach, break, breakage, broaching, burst, caesura, canyon, cavity, cessation, chap, chasm, check, chimney, chink, chip, clearing, cleavage, cleave, cleft, cleuch, clough, clove, col, coulee, couloir, crack, cranny, crevasse, crevice, cut, cut apart, cwm, dale, defalcation, defect, deficiency, deficit, defile, dehisce, delay, dell, difference, dike, dingle, disagreement, disclosure, discontinuity, discrepancy, disparity, disruption, distance, distinction, ditch, divergence, division, donga, draw, excavation, fault, fenestra, fissure, fistula, flaw, flume, fontanel, foramen, fracture, furrow, gape, gash, gat, gill, glen, gorge, groove, grove, gulch, gulf, gully, halt, hang open, hiatus, hole, hollow, incise, incision, inconsistency, inlet, interim, intermission, interruption, interspace, interval, intervale, joint, kloof, lack, lacuna, laying open, leak, letup, lull, lunar rill, missing link, moat, need, notch, nullah, omission, open, opening, opening up, orifice, oscitate, outage, outlet, pass, passage, passageway, pause, pore, ravine, recess, rent, respite, rest, rift, rime, rip, rive, rupture, scale, scissure, seam, separation, shortage, slash, slice, slit, slot, space, splinter, split, stoma, stop, strath, suspension, tear, throwing open, trench, trough, ullage, uncorking, unstopping, vale, valley, void, wadi, wait, want, wantage, yawn