• WordNet 3.6
    • v rarefy weaken the consistency of (a chemical substance)
    • v rarefy make more subtle or refined
    • v rarefy lessen the density or solidity of "The bones are rarefied"
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Webster's Revised Unabridged Dictionary
    • v. i Rarefy To become less dense; to become thin and porous. "Earth rarefies to dew."
    • v. t Rarefy To make rare, thin, porous, or less dense; to expand or enlarge without adding any new portion of matter to; -- opposed to condense.
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Century Dictionary and Cyclopedia
    • rarefy To make rare, thin, porous, or less dense; expand or enlarge without adding any new matter; figuratively, to spread or stretch out; distend: opposed to condense.
    • rarefy To become rare; pass into a thinner or less dense condition.
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Chambers's Twentieth Century Dictionary
    • v.t Rarefy (rar′e-fī, or rā′re-fī) to make rare, thin, or less dense: to expand a body
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Webster's Revised Unabridged Dictionary
F. raréfier,; L. rarus, rare + -ficare,in comp.) to make; cf. L. rarefacere,. See -fy
Chambers's Twentieth Century Dictionary
Fr.,—L. rārus.


In literature:

The rarefied air of the Plateau with its cold winds and lower temperatures, just now about -10 deg.
"The Worst Journey in the World, Volumes 1 and 2" by Apsley Cherry-Garrard
When the brush is obtained in rarefied air, the appearances vary greatly, according to circumstances, and are exceedingly beautiful.
"Experimental Researches in Electricity, Volume 1" by Michael Faraday
Hitherto we had breathed the rarefied air of the peaks, seen the white light of the upper spaces, felt the passionless gods about us.
"Children of the Market Place" by Edgar Lee Masters
From a primitive passion it had become a rarefied emotional atmosphere in which she lived and moved.
"Far to Seek" by Maud Diver
The birds had long since forsaken us; in this rarefied sir their flight would have been impossible.
"A Voyage in a Balloon (1852)" by Jules Verne
But its atmosphere is becoming daily more rarefied.
"Musicians of To-Day" by Romain Rolland
In our study of the atmosphere we saw that air can be compressed and rarefied; in other words, we saw that air is very elastic.
"General Science" by Bertha M. Clark
Heat acting upon air rarefies it, by which it becomes specifically lighter, and mounts upward.
"The History of Sumatra" by William Marsden
The air seemed rarefied; we were panting, with our cheeks tingling.
"The White Invaders" by Raymond King Cummings
Has the rarefied air of the mountains upset your brain?
"The Black Wolf Pack" by Dan Beard

In news:

EMERYVILLE, Calif, Oct 9— In the rarefied world of biotechnology, the Chiron Corporation has always had the respect of its peers.
But he has stealthily climbed into some rarefied air in Georgia's receiving record book.
John Moriarty, whiskey expert and bar manager at Ireland's Park Hotel Kenmare, holds the key to the cabinet displaying the rarefied whiskeys that aficionados stare at longingly.
The rarefied world of classical music is the setting and the intimate "perfect square" of a string quartet the crucible for.
Allen West, the tea party-backed Republican from Plantation, is no stranger to odd headlines, but this week's twofer, during an interview with CNN's Soledad O'Brien, places him in rarefied knucklehead territory.
His new global media strategy is equally rarefied, and only occasionally ridiculous.
Pianist Fred Hersch reaches some rarefied heights on this wise trio recording with bassist John Herbert and drummer Eric McPherson.
Inside the Rarefied Heads of Jim Dahlgren and Allan Duck.
North Dakota's booming economy gives the political dynamic a rarefied air.
Romney mixes and mingles at rarefied retreat as top donors taste victory.
In Rarefied Sport, a View of the Romneys' World.
BYU's Miles Batty looking to join rarefied air Saturday in Provo.
Red Wings star Nicklas Lidstrom in rarefied air.
Musician's career spanned the bump and grind of Block burlesque houses to the rarefied atmosphere of the Baltimore Symphony Orchestra and academe.
Ever since Being John Malkovich, everyone's been dying to climb into Malkovich's mind in order to appreciate the extremely rarefied air up there.

In science:

On Mot ion Energy of Free Quantum Part icles in Rarefied Beams. Ingenernaya Physika Journal. 2009.
Quantum Physics and Nanotechnology
Hence Coulomb collisions are very rare and electric and magnetic fields, instead, mediate particle-particle interactions. Explosions in such rarefied plasma also drive shock waves, but these shocks are very different from their hydrodynamic counterparts and are referred to as “collisionless”.
Kinetics of Particles in Relativistic Collisionless Shocks
Imagine that the sphere of radius ro, containing positive mass matter, is surrounded by an extremely rarefied medium.
Bigravity : A bimetric model of the Universe. Positive and negative gravitational lensings
W. Steckelmacher, "Knudsen flow 75 years on: the current state of the art for flow of rarefied gases in tubes and systems," Rep.
A molecular dynamics test of the Navier-Stokes-Fourier paradigm for compressible gaseous continua
Shen, Rarefied Gas Dynamics (Springer, Berlin, 2005).
A molecular dynamics test of the Navier-Stokes-Fourier paradigm for compressible gaseous continua