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!.
stopper, stopple, plug, cork, bung, spike, spill, stopcock, tap, rammer, ram, ramrod, piston, stop-gap, wadding, stuffing, padding, stopping, dossil, pledget, tompion, tourniquet, cover, valve, vent peg, spigot, slide valve, janitor, doorkeeper, porter, warder, beadle, cerberus, ostiary
gulf, lake, land covered with water, gulf, gulph, bay, inlet, bight, estuary, arm of the sea, bayou, fiord, armlet, frith, firth, ostiary
, mouth, lagune, lagoon, indraught, cove, creek, natural harbor, roads, strait, narrows, Euripus, sound, belt, gut, kyles, continental slope, continental shelf, lake, loch, lough, mere, tarn, plash, broad, pond, pool, lin, puddle, slab, well, artesian well, standing water, dead water, sheet of water, fish pond, mill pond, ditch, dike, dyke, dam, reservoir, alberca, barachois, hog wallow, lacustrine.