smog

noun

ˈsmäg How to pronounce smog (audio)
ˈsmȯg
: a fog made heavier and darker by smoke and chemical fumes
also : a photochemical haze caused by the action of solar ultraviolet radiation on atmosphere polluted with hydrocarbons and oxides of nitrogen especially from automobile exhaust
smogless
ˈsmä-gləs How to pronounce smog (audio)
ˈsmȯ-
adjective

Examples of smog in a Sentence

the city's smog was once so bad that darkness often prevailed, even at noon
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
According to Citizens’ Climate Lobby, burning fossil fuels releases a mix of harmful pollutants including carbon dioxide, sulfur dioxide, nitrogen oxides, and particulate matter that contribute to global warming, smog, acid rain, and severe respiratory illnesses. Dianne Plummer, Forbes.com, 22 May 2025 However, the season, time of day, cloud coverage, smog, and sunscreen can affect how much vitamin D3 your body makes from the sun. Health, 20 May 2025 The turbines give off nitrogen oxides, a key contributor to smog, and formaldehyde, among other pollutants, according to their manufacturer. Stephanie Gosk, NBC news, 15 May 2025 In our lifetimes, cities were clogged with smog, which contained plenty of lead belched from then-leaded gasoline. New York Daily News Editorial Board, New York Daily News, 23 Apr. 2025 See All Example Sentences for smog

Word History

Etymology

smoke + fog

First Known Use

1880, in the meaning defined above

Time Traveler
The first known use of smog was in 1880

Browse Nearby Words

Cite this Entry

“Smog.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/smog. Accessed 29 May. 2025.

Kids Definition

smog

noun
ˈsmäg How to pronounce smog (audio)
 also  ˈsmȯg
: a thick haze caused by the action of sunlight on air polluted especially by smoke and automobile exhaust fumes
Etymology

from smoke and fog

Medical Definition

smog

noun
ˈsmäg also ˈsmȯg
: a fog made heavier and darker by smoke and chemical fumes
also : a photochemical haze caused by the action of solar ultraviolet radiation on atmosphere polluted with hydrocarbons and oxides of nitrogen especially from automobile exhaust

More from Merriam-Webster on smog

Last Updated: - Updated example sentences
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