ROGET THESAURUS
sponginess
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.