THESAURUS
chasm
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
ROGET THESAURUS
chasm
Interval
N
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
N
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!.