smog

noun

ˈsmäg 

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 

ˈsmȯ-

adjective

Synonyms of smog

• haze
• fog
• cloud
• mist

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

In the end, neither the altitude, nor the smog, nor more than 80,000 fans were decisive factors in the final outcome of a game in which England’s superior roster filled with Premier League talent controlled the result. — Eduard Cauich, Los Angeles Times, 6 July 2026

The summer gasoline blend rules, which have been in effect since 1996, are intended to prevent the release of smog-causing particles into the air, the Michigan Department of Agriculture and Rural Development said. — Paula Wethington, CBS News, 29 June 2026

What was once the season of patios and long days has increasingly turned into one of heat advisories, wildfire smoke, and smog alerts. — Alexandra Emanuelli, Travel + Leisure, 28 June 2026

California has long held special authority under the federal Clean Air Act to set stricter emissions standards than the federal government because of the state’s historic smog problems. — Haley Parsley june 22, Sacbee.com, 23 June 2026

Word History

Etymology

smoke + fog

First Known Use

1880, in the meaning defined above

Phrases Containing smog

• anti-smog

Rhymes for smog

• blog
• bog
• clog
• cog
• dog
• flog
• fog
• frog
• grog
• hog
• jog
• log

Kids 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

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