THESAURUS
abysmal, abyssal, boat-shaped, boatlike, bottomless, bowl-shaped, bowllike, cavelike, commodious, concave, concaved, craterlike, cup-shaped, cupped, cymbiform, deep as hell, dish-shaped, dished, dishing, dishlike, fathomless, funnel-breasted, funnel-chested, funnel-shaped, gaping, hollow, hollowed, incurved, incurving, incurvous, infundibular, infundibuliform, navicular, naviform, plumbless, plunging, retiring, retreating, reverberant, saucer-shaped, scaphoid, scyphate, sepulchral, soundless, spoonlike, sunk, sunken, unfathomable, unfathomed, unsounded, vast, without bottom, yawning
ROGET THESAURUS
Concavity
N
concavity, depression, dip, hollow, hollowness, indentation, intaglio, cavity, dent, dint, dimple, follicle, pit, sinus, alveolus, lacuna, excavation, strip mine, trough, honeycomb, cup, basin, crater, punch bowl, cell, socket, valley, vale, dale, dell, dingle, combe, bottom, slade, strath, glade, grove, glen, cave, cavern, cove, grot, grotto, alcove, cul-de- sac, gully, arch, bay, excavator, sapper, miner, honeycomb (sponge), depressed, alveolate, calathiform, cup-shaped, dishing, favaginous, faveolate, favose, scyphiform, scyphose, concave, hollow, stove in, retiring, retreating,
cavernous, porous, infundibul, infundibular, infundibuliform, funnel shaped, bell shaped, campaniform, capsular, vaulted, arched.
Rarity
N
rarity, tenuity, absence of solidity, subtility, subtilty, subtlety, sponginess, compressibility, rarefaction, expansion, dilatation, inflation, subtilization, vaporization, evaporation, diffusion, gassification, ether, rare, subtile, thin, fine, tenuous, compressible, flimsy, slight, light,
cavernous, spongy, rarefied, unsubstantial, uncompact, incompressed, rarefiable.