abysm, abyss, aperture, arroyo, blank, box canyon, breach, break, broaching, canyon, cavity, chap, check, chimney, chink, clearing, cleavage, cleft, cleuch, clough, clove, col, coulee, couloir, crack, cranny, crater, crevasse, crevice, cut, cwm, deep, defile, dell, depth, dig, diggings, dike, disclosure, ditch, donga, draw, excavation, fault, fenestra, fissure, fistula, flaw, flume, fontanel, foramen, fracture, furrow, gap, gape, gash, gat, gorge, groove, gulch, gulf, gully, hiatus, hole, hollow, incision, inlet, interval, joint, kloof, lacuna, laying open, leak, mine, moat, notch, nullah, opening, opening up, orifice, outlet, overlook, oversight, pass, passage, passageway, pit, pore, preterition, quarry, ravine, rent, rift, rime, rupture, scissure, seam, shaft, skip, slit, slot, space, split, stoma, throwing open, trench, uncorking, unstopping, valley, void, wadi, well, workings, yawn, yawning abyss
interval, interspace, separation, break, gap, opening, hole, chasm
, hiatus, caesura, interruption, interregnum, interstice, lacuna, cleft, mesh, crevice, chink, rime, creek, cranny, crack, chap, slit, fissure, scissure, rift, flaw, breach, rent, gash, cut, leak, dike, ha-ha, gorge, defile, ravine, canon, crevasse, abyss, abysm, gulf, inlet, frith, strait, gully, pass, furrow, abra, barranca, barranco, clove, gulch, notch, yawning gulf, hiatus maxime, hiatus valde deflendus, parenthesis, void, incompleteness, period, interim (time), with an interval, far between, breachy, rimose, rimulose, at intervals, longo intervallo.
opening, hole, foramen, puncture, perforation, fontanel, transforation, pinhole, keyhole, loophole, porthole, peephole, mousehole, pigeonhole, eye of a needle, eyelet, slot, opening, aperture, apertness, hiation, yawning, oscitancy, dehiscence, patefaction, pandiculation, chasm
, embrasure, window, casement, abatjour, light, sky light, fan light, lattice, bay window, bow window, oriel, dormer, lantern, outlet, inlet, vent, vomitory, embouchure, orifice, mouth, sucker, muzzle, throat, gullet, weasand, wizen, nozzle, placket, portal, porch, gate, ostiary, postern, wicket, trapdoor, hatch, door, arcade, cellarway, driveway, gateway, doorway, hatchway, gangway, lich gate, way, path, thoroughfare, channel, passage, passageway, tube, pipe, water pipe, air pipe, vessel, tubule, canal, gut, fistula, adjutage, ajutage, ostium, smokestack, chimney, flue, tap, funnel, gully, tunnel, main, mine, pit, adit, shaft, gallery, alley, aisle, glade, vista, bore, caliber, pore, blind orifice, fulgurite, thundertube, porousness, porosity, sieve, cullender, colander, cribble, riddle, screen, honeycomb, apertion, perforation, piercing, terebration, empalement, pertusion, puncture, acupuncture, penetration, key, opener, master key, password, combination, passe- partout, open, perforated, perforate, wide open, ajar, unclosed, unstopped, oscitant, gaping, yawning, patent, tubular, cannular, fistulous, pervious, permeable, foraminous, vesicular, vasicular, porous, follicular, cribriform, honeycombed, infundibular, riddled, tubulous, tubulated, piped, tubate, opening, aperient, Int, open sesame!.