• synonyms


[rair-uh-fak-shuh n]
See more synonyms on Thesaurus.com
  1. the act or process of rarefying.
  2. the state of being rarefied.

Origin of rarefaction

1595–1605; < Medieval Latin rārēfactiōn- (stem of rārēfactiō), equivalent to Latin rārēfact(us) (past participle of rārēfacere; see rarefy) + -iōn- -ion
Related formsrar·e·fac·tion·al, adjectiverar·e·fac·tive [rair-uh-fak-tiv] /ˌrɛər əˈfæk tɪv/, adjective
Can be confuseddiffraction diffusion reflection rarefaction refraction
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for rarefaction

Historical Examples

  • Rarefaction and condensation by instruments were also tried, but in vain.

    Experiments and Observations on Different Kinds of Air

    Joseph Priestley

  • Also, rarefaction by the air-pump does not injure air in the least degree.

  • With these pumps a higher degree of rarefaction can be obtained.


    Willis Eugene Tower

  • Waves: transverse, longitudinal; wave length, condensation, rarefaction.


    Willis Eugene Tower

  • Indicate the parts of the curve that correspond to a condensation and to a rarefaction.


    Willis Eugene Tower

British Dictionary definitions for rarefaction


rarefication (ˌrɛərɪfɪˈkeɪʃən)

  1. the act or process of making less dense or the state of being less dense
Derived Formsrarefactional, rareficational or rarefactive, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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

rarefaction in Medicine


  1. 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.

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 © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.