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[smog, smawg] /smɒg, smɔg/
smoke or other atmospheric pollutants combined with fog in an unhealthy or irritating mixture.
verb (used with object)
to cover or envelop with or as if with smog.
Origin of smog
1900-05; sm(oke) + (f)og1
Related forms
smogless, adjective
desmog, verb (used with object), desmogged, desmogging. Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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British Dictionary definitions for smog


a mixture of smoke, fog, and chemical fumes
Derived Forms
smoggy, adjective
Word Origin
C20: from sm(oke + f)og1
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
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Word Origin and History for smog

1905, blend of smoke and fog, formed "after Lewis Carrol's example" [Klein; see portmanteau]. Reputedly coined in reference to London, and first attested there in a paper read by Dr. H.A. des Voeux, treasurer of the Coal Smoke Abatement Society, though he seems not to have claimed credit for coining it.

At a recent health congress in London, a member used a new term to indicate a frequent London condition, the black fog, which is not unknown in other large cities and which has been the cause of a great deal of bad language in the past. The word thus coined is a contraction of smoke fog "smog" -- and its introduction was received with applause as being eminently expressive and appropriate. It is not exactly a pretty word, but it fits very well the thing it represents, and it has only to become known to be popular. ["Journal of the American Medical Association," Aug. 26, 1905]
Smaze (with haze (n.)) is from 1953.

Online Etymology Dictionary, © 2010 Douglas Harper
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smog in Medicine

smog (smŏg)

  1. Fog that has become mixed and polluted with smoke.

  2. A form of air pollution produced when sunlight causes hydrocarbons and nitrogen oxides from automotive emissions to combine in a photochemical reaction.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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smog in Science
  1. A form of air pollution produced by the reaction of sunlight with hydrocarbons, nitrogen compounds, and other gases primarily released in automobile exhaust. Smog is common in large urban areas, especially during hot, sunny weather, where it appears as a brownish haze that can irritate the eyes and lungs. Ozone, a toxic gas that is not normally produced at lower atmospheric levels, is one of the primary pollutants created in this kind of smog. Also called photochemical smog.

  2. Fog that has become polluted with smoke and particulates, especially from burning coal.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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smog in Culture

smog definition

A haze or fog composed of water vapor, complex molecules, and suspended particles.

Note: In North America, the primary cause of smog is pollution from automobile exhaust.
Note: The Los Angeles basin, where pollutants can be trapped by inversions and the surrounding mountains, has frequent problems with smog, as do other major urban areas.
Note: The word smog is a combination of smoke and fog.
The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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