gap, opening, crack, hole, rift, break, breach, cleft, split, rent, crevice, chink, aperture, slit, fracture, cranny, interstice, rupture, chasm, vent, gash, crater, crevasse, cleavage, fault, groove, scission, grike, space, void, hiatus, gulf, discontinuity, cut, orifice, tear, slot, separation, cavity, interval, perforation, check, division, puncture, foramen, rip, pit, slash, outlet, rime … more

gaps, openings, crack, holes, rifts, breaks, breaches, clefts, splits, rent, crevices, chinks, apertures, slits, fractures, crannies, interstices, rupture, chasms, vents, gashes, craters, crevasses, cleavage, faults, grooves, scissions, grikes, gulfs, voids, cavities, space, hiatus, cuts, discontinuities, separation, tears, slots, orifices, gorges, intervals, checks, perforation, pits, ravines, canyons, hollows, gulches, abysses, notches … more