[ smog, smawg ]
/ smɒg, smɔg /
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Definition of smog

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.
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Origin of smog

1900–05; sm(oke) + (f)og1


smogless, adjectivede·smog, verb (used with object), de·smogged, de·smog·ging.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use smog in a sentence

British Dictionary definitions for smog

/ (smɒɡ) /

a mixture of smoke, fog, and chemical fumes

Derived forms of smog

smoggy, adjective

Word Origin for smog

C20: from sm (oke + f) og 1
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

Medical definitions for smog

[ smŏg ]

Fog that has become mixed and polluted with smoke.
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.

Scientific definitions for smog

[ smŏg ]

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
Fog that has become polluted with smoke and particulates, especially from burning coal.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for smog


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

notes for smog

In North America, the primary cause of smog is pollution from automobile exhaust.

notes for smog

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.

notes for smog

The word smog is a combination of smoke and fog.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.