noun
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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.
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Also called photochemical smog
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Fog that has become polluted with smoke and particulates, especially from burning coal.
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In North America, the primary cause of smog is pollution from automobile exhaust.
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.
The word smog is a combination of smoke and fog.
Other Word Forms
- desmog verb (used with object)
- smoggy adjective
- smogless adjective
Etymology
Origin of smog
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Typically, sales of the gas are restricted during the summer due to the volatility of ethanol and its contribution to smog, but the Farm Bureau maintains that new studies show the blend is non-polluting.
From Los Angeles Times
“Today we can say all aboard on what will be the highest ridership light rail in the country, easier commutes, less smog, more access to housing.”
From Los Angeles Times
But as we would find out, our smog — photochemical smog — made the air taste like poison and look like something you’d put out with the garbage.
From Los Angeles Times
It was this: “I mean, we’ve got enough smog in Los Angeles, let alone to deal with setting these fires and things.”
From Los Angeles Times
When it comes to smog, let’s not congratulate ourselves too much; it was technology that did the heavy lifting, not demanding much in the way of sacrifice or even change in our behavior.
From Los Angeles Times
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.