[dih-spur-zhuh n, -shuh n]


Also dispersal. an act, state, or instance of dispersing or of being dispersed.
  1. the variation of the index of refraction of a transparent substance, as glass, with the wavelength of light, with the index of refraction increasing as the wavelength decreases.
  2. the separation of white or compound light into its respective colors, as in the formation of a spectrum by a prism.
Statistics. the scattering of values of a variable around the mean or median of a distribution.
Military. a scattered pattern of hits of bombs dropped under identical conditions or of shots fired from the same gun with the same firing data.
Also called disperse system. Physical Chemistry. a system of dispersed particles suspended in a solid, liquid, or gas.
(initial capital letter) Diaspora(def 1).

Origin of dispersion

1350–1400; Middle English dispersio(u)n (< Anglo-French) < Latin dispersiōn- (stem of dispersiō), equivalent to dispers(us) (see disperse) + -iōn- -ion
Related formsnon·dis·per·sion, nounpre·dis·per·sion, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for dispersion

diffusion, distribution, scattering

Examples from the Web for dispersion

Contemporary Examples of dispersion

Historical Examples of dispersion

British Dictionary definitions for dispersion



another word for dispersal
  1. the separation of electromagnetic radiation into constituents of different wavelengths
  2. a measure of the ability of a substance to separate by refraction, expressed by the first differential of the refractive index with respect to wavelength at a given value of wavelengthSymbol: D
statistics the degree to which values of a frequency distribution are scattered around some central point, usually the arithmetic mean or median
chem a system containing particles dispersed in a solid, liquid, or gas
military the pattern of fire from a weapon system
  1. the range of speeds of such objects as the stars in a galaxy
  2. the frequency-dependent retardation of radio waves as they pass through the interstellar medium
  3. the deviation of a rocket from its prescribed path
ecology the distribution pattern of an animal or a plant population



the Dispersion another name for the Diaspora
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 dispersion

late 14c., from Old French dispersion (13c.), from Latin dispersionem (nominative dispersio) "a scattering," noun of action from past participle stem of dispergere (see disperse).

Online Etymology Dictionary, © 2010 Douglas Harper

dispersion in Medicine




The act or process of dispersing.
The state of being dispersed.
Disperse system.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

dispersion in Science



The separation by refraction of light or other radiation into individual components of different wavelengths. Dispersion results in most materials because a material's index of refraction depends on the wavelength of the radiation passing through it; thus different wavelengths entering a material along the same path will fan out into different paths within it. Prisms, for example, diffuse white light (which contains an even mixture of visible wavelengths) into its variously colored components; rainbows are an effect of dispersion in water droplets.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.