rarefaction

• POS: Noun
• HYPHEN: rar=e=fac=tion

CIDE DICTIONARY

rarefaction, n. [Cf. F. raréfaction. See Rarefy.].

 The act or process of rarefying; the state of being rarefied; -- opposed to condensation; as, the rarefaction of air.  [1913 Webster]

ROGET THESAURUS

rarefaction

Expansion

N expansion, increase of size, enlargement, extension, augmentation, amplification, ampliation, aggrandizement, spread, increment, growth, development, pullulation, swell, dilation, rarefaction, turgescence, turgidness, turgidity, dispansion, obesity, hydrocephalus, hydrophthalmus, dropsy, tumefaction, intumescence, swelling, tumor, diastole, distension, puffing, puffiness, inflation, pandiculation, dilatability, expansibility, germination, growth, upgrowth, accretion, budding, gemmation, overgrowth, overdistension, hypertrophy, tympany, bulb, plumper, superiority of size, big bang, Hubble constant, expanded larger, &c (large), swollen, expansive, wide open, wide spread, flabelliform, overgrown, exaggerated, bloated, fat, turgid, tumid, hypertrophied, dropsical, pot bellied, swag bellied, edematous, oedematous, obese, puffy, pursy, blowzy, bigswoln, distended, patulous, bulbous, full blown, full grown, full formed, big, abdominous, enchymatous, rhipidate, tumefacient, tumefying.

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.