Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “smog”

smog

noun [C/U]  /smɑɡ, smɔɡ/ us  
air pollution caused by smoke or chemicals mixing with fog: [U] We get a lot of smog downtown. [C] A poisonous smog killed 20 people.
smoggy
adjective  /ˈsmɑɡ·i, ˈsmɔ·ɡi/ us  
a smoggy city/day
(Definition of smog from the Cambridge Academic Content Dictionary © Cambridge University Press)
What is the pronunciation of smog?
Add Cambridge dictionaries to your browser to your website

Definitions of “smog” in other dictionaries

Word of the Day

innovate

to introduce changes and new ideas

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More