: 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
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
Its three-stage filtration is designed to target pollutants such as smog and smoke, pet dander, hair, and other allergens.
—
Toni Sutton, People.com, 28 Oct. 2024
Dystopian scenes of orange haze and buildings enveloped by fog emerge each year as smog season dominates the news, raising alarm as doctors warn of the risk of respiratory diseases and impacts on life expectancy.
—Noemi Cassanelli, CNN, 28 Oct. 2024
The greenhouse gas rating is a 5, and the smog rating is a 7; both out of 10.
—Tony Leopardo, The Mercury News, 20 Oct. 2024
Carbon emissions, and other greenhouse gases from human activity, cause long-term shifts in temperatures and weather, while also contributing to respiratory disease by forming smog and air pollution.
—Ryan Browne,lora Kolodny, CNBC, 8 Oct. 2024
See all Example Sentences for smog 
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Toni Sutton, People.com, 28 Oct. 2024
Dystopian scenes of orange haze and buildings enveloped by fog emerge each year as smog season dominates the news, raising alarm as doctors warn of the risk of respiratory diseases and impacts on life expectancy.
—Noemi Cassanelli, CNN, 28 Oct. 2024
The greenhouse gas rating is a 5, and the smog rating is a 7; both out of 10.
—Tony Leopardo, The Mercury News, 20 Oct. 2024
Carbon emissions, and other greenhouse gases from human activity, cause long-term shifts in temperatures and weather, while also contributing to respiratory disease by forming smog and air pollution.
—Ryan Browne,lora Kolodny, CNBC, 8 Oct. 2024
See all Example Sentences for smog
Dictionary Entries Near smog
Cite this Entry
“Smog.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/smog. Accessed 7 Nov. 2024.
Copy CitationKids Definition
smog
noun
ˈsmäg 
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
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