Africa, Antarctica, Asia, Australia, Eurasia, Eurasian landmass, Europe, North America, South America, absolute, all-absorbing, arch, awful, banner, basic, big, big drink, biggest, blue, blue water, brine, briny, brute, capital, cardinal, central, champion, channel, chief, cock, comprehensive, conduit, consequential, considerable, continent, controlling, crazy, critical, crowning, crucial, damned, deep, dominant, dreadful, drink, duct, effort, electric cable, energy, essential, exceedingly, exhaustive, extremely, fire main, first, focal, foremost, front, full, fundamental, gas main, grand, grave, great, greatest, head, headmost, heavy, hegemonic, high sea, high seas, highest, hydrosphere, in the main, intense, irresistible, landmass, largest, larruping, leading, line, magisterial, maiden, main sea, mainland, mainly, mains, major, master, maximum, mere, might, mighty, monstrous, necessary, ocean, ocean depths, ocean main, ocean sea, out-and-out, outstanding, overriding, overruling, paramount, particular, peninsula, pipe, pipeline, plain, plenary, power, power supply, powerful, predominant, predominating, preeminent, premier, preponderant, prevailing, primal, primary, prime, principal, pure, ranking, ruling, salt sea, salt water, sea, serious, sheer, sovereign, star, stellar, strength, strong, strongest, subcontinent, supereminent, supreme, thalassa, the bounding main, the brine, the briny, the briny deep, the deep, the deep sea, the seven seas, the vasty deep, tide, topflight, topmost, total, uppermost, utter, vigor, vital, water main
importance, consequence, moment, prominence, consideration, mark, materialness, import, significance, concern, emphasis, interest, greatness, superiority, notability, weight, value, usefulness, gravity, seriousness, solemnity, no joke, no laughing matter, pressure, urgency, stress, matter of life and death, memorabilia, notabilia, great doings, red-letter day, great thing, great point, main chance, the be all and the end all, cardinal point, substance, gist, sum and substance, gravamen, head and front, important part, principal part, prominent part, essential part, half the battle, sine qua non, breath of one's nostrils, cream, salt, core, kernel, heart, nucleus, keynote, keystone, corner stone, trump card, salient points, top sawyer, first fiddle, prima donna, chief, triton among the minnows, 'it', important, of importance, momentous, material, to the point, not to be overlooked, not to be despised, not to be sneezed at, egregious, weighty, of note, notable, prominent, salient, signal, memorable, remarkable, unforgettable, worthy of remark, worthy of notice, never to be forgotten, stirring, eventful, grave, serious, earnest, noble, grand, solemn, impressive, commanding, imposing, urgent, pressing, critical, instant, paramount, essential, vital, all-absorbing, radical, cardinal, chief, main, prime, primary, principal, leading, capital, foremost, overruling, of vital importance in the front rank, first-rate, superior, considerable, marked, rare, significant, telling, trenchant, emphatic, pregnant, tanti, materially, in the main, above all, kat' exochin, par excellence, to crown all, to beat all, expende Hannibalem!.
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!.
sea, ocean, main, deep, brine, salt water, waves, billows, high seas, offing, great waters, watery waste, vasty deep, wave, tide, hydrography, hydrographer, Neptune, Poseidon, Thetis, Triton, Naiad, Nereid, sea nymph, Siren, trident, dolphin, oceanic, marine, maritime, pelagic, pelagian, seagoing, hydrographic, bathybic, cotidal, at sea, on sea, afloat.
conduit, channel, duct, watercourse, race, head race, tail race, abito, aboideau, aboiteau, bito, acequia, acequiador, acequiamadre, arroyo, adit, aqueduct, canal, trough, gutter, pantile, flume, ingate, runner, lock-weir, tedge, vena, dike, main, gully, moat, ditch, drain, sewer, culvert, cloaca, sough, kennel, siphon, piscina, pipe, funnel, tunnel, water pipe, waste pipe, emunctory, gully hole, artery, aorta, pore, spout, scupper, adjutage, ajutage, hose, gargoyle, gurgoyle, penstock, weir, flood gate, water gate, sluice, lock, valve, rose, waterworks, pipeline, vascular.