Synonyms and related words :
abysm, abyss, alveolation, alveolus, antrum, aperture, armpit, arroyo, basin, booth, bowl, box, box canyon, breach, break, broaching, canyon, cell, cellule, chamber, chap, chasm, check, chimney, chink, clearing, cleft, cleuch, clough, col, compartment, concave, concavity, coulee, couloir, crack, cranny, crater, crevasse, crevice, crib, crypt, cup, cut, cwm, deep, defile, dell, depression, depth, dike, dip, disclosure, ditch, donga, draw, enclosed space, excavation, fault, fenestra, fissure, fistula, flaw, flume, fold, follicle, fontanel, foramen, fracture, funnel chest, furrow, gap, gape, gash, gat, gorge, groove, gulch, gulf, gully, hiatus, hold, hole, hollow, hollow shell, incision, inlet, interval, joint, kloof, lacuna, laying open, leak, manger, moat, notch, nullah, opening, opening up, orifice, outlet, pass, passage, passageway, pew, pit, pocket, pore, punch bowl, ravine, rent, rift, rime, rupture, scissure, scoop, seam, shaft, shell, sink, sinus, slit, slot, socket, space, split, stall, stoma, throwing open, trench, trough, uncorking, unstopping, vacuity, valley, vault, void, vug, wadi, well, yawn, yawning abyss,