cavern Definition

cavern out, cave, grotto, antre, cave-in, cavelike, stalactite, catacomb, cenote, underground, dungeon, tunnel, passageway, labyrinth, crevice, canyon, volcanic crater, crypt, waterfall, crater, sinkhole, tomb, hypogeum, quarry, burrow, limestone, crag, basement, cavernicolous, incaverned, mineshaft, incaved, kiva, reservoir, dome, fumarole, fumaroles, shaft, bathysphere, potholer, stalagmites, rockface, spelunk, carlsbad caverns, rupestrian, refugium, airlock, crevasses, cistern, dolerite, hogback, manhole, trench, rock outcrop, ventilation shaft, spelunkers, depths, excavation, coal mine, sandstone, natural depression, snowfield, gasometer, crawlspace, sarcophagus, cofferdam, spiral staircase, baptistry, staircase, lava, snailfish, reservior, tumulus, stairway, cheops, stalagmite, postholes, slickrock, lair, glacial boulder, apses, abysses, trackway, cavity, baptistery, oculus, lanternfish, subbasement, manway, hole, tartarus, mountainside, bowels, halite, hibernaculum, atacama desert, esker, root cellar, bivvy, coalhole,