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[rair-uh-fak-shuh n] /ˌrɛər əˈfæk ʃən/
the act or process of rarefying.
the state of being rarefied.
1595-1605; < Medieval Latin rārēfactiōn- (stem of rārēfactiō), equivalent to Latin rārēfact(us) (past participle of rārēfacere; see rarefy) + -iōn- -ion
Related forms
rarefactional, adjective
[rair-uh-fak-tiv] /ˌrɛər əˈfæk tɪv/ (Show IPA),
Can be confused Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for rarefaction
  • Cross-compatible cartridge case for orthodox or rarefaction wave gun firing.
British Dictionary definitions for rarefaction


the act or process of making less dense or the state of being less dense
Derived Forms
rarefactional, rareficational, rarefactive, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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Word Origin and History for rarefaction

c.1600, from Middle French raréfaction or directly from Medieval Latin rarefactionem (nominative rarefactio), noun of action from past participle stem of Latin rarefacere (see rarefy). Used chiefly in reference to gasses.

Online Etymology Dictionary, © 2010 Douglas Harper
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rarefaction in Medicine

rarefaction rar·e·fac·tion (râr'ə-fāk'shən)
A decrease in density and pressure in a medium, such as air, caused by the passage of a sound wave.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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rarefaction in Science
  1. A decrease in density and pressure in a medium, such as air, especially when caused by the passage of a wave, such as a sound wave.

  2. The region in which this occurs.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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Encyclopedia Article for rarefaction

in the physics of sound, segment of one cycle of a longitudinal wave during its travel or motion, the other segment being compression. If the prong of a tuning fork vibrates in the air, for example, the layer of air adjacent to the prong undergoes compression when the prong moves so as to squeeze the air molecules together. When the prong springs back in the opposite direction, however, it leaves an area of reduced air pressure. This is rarefaction. A succession of rarefactions and compressions makes up the longitudinal wave motion that emanates from an acoustic source

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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