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.
Fed up with the government’s inaction, a group of residents created Polish Smog Alert, an advocacy organization pushing for legislation to suppress the smog. Cecilia Rodriguez, Forbes.com, 29 June 2025 The poor air quality is forecast to be an orange ozone alert, which means an unhealthy level of ground-level ozone, known as ozone pollution or smog, is expected for people sensitive to pollution, according to the agency, known as MARC. Ramal Nasim, Kansas City Star, 18 June 2025 The base experiences temperatures exceeding 100 degrees Fahrenheit and persistent poor air quality because of local burn pits, which emit smog and have caused respiratory illness among both officers and detainees. Billal Rahman, MSNBC Newsweek, 6 June 2025 How about no smog checks for cars with a consistently low smog reading? Jim Radcliffe, Oc Register, 23 May 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 5 Jul. 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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