Meaning & use
smog
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Meanings
noununcountable
Thick, dirty air over a city, made when pollution from traffic and factories mixes with fog or hot sunny weather.
Grammar: Takes no article for the general idea: smog hung over the valley.
Patterns
- smog over something
Thick smog covered the city on Tuesday.
Schools closed because of the heavy smog.
Smog makes it harder for people with asthma to breathe.
noununcountabletechnical
A haze of pollutants formed when sunlight reacts with vehicle exhaust, called photochemical smog.
Grammar: Common in warm, dry cities with heavy traffic.
Photochemical smog forms on hot afternoons.
Scientists studied how sunlight turns exhaust into smog.
Common combinations
- thick smog
- Thick smog blotted out the skyline.
- photochemical smog
- Photochemical smog is common in sunny cities.
- smog alert
- A smog alert warned residents to stay indoors.
- blanket of smog
- A blanket of smog covered the town.
- reduce smog
- New rules aim to reduce smog.
Synonyms and how they differ
- haze
- Haze is any thin cloud in the air, and need not come from pollution.
- fog
- Fog is water droplets in the air and is natural, unlike smog.
- air pollution
- Air pollution is the broad problem, while smog is one visible form of it.
- fumes
- Fumes are harmful gases or smoke from a source, and not the city-wide haze.
Opposites
Word family
- smoggy adjective
- filled with smog
- smogless adjective
- free of smog, rare
- antismog adjective
- designed to reduce smog
Commonly confused: smog or fog?
smog vs fog
Fog is a natural cloud at ground level, while smog is polluted air.
Practice
Which word is a blend of smoke and fog?
Choose one answer.
Smog was formed from smoke and fog. Haze and mist are natural, and soot is black particles.
Make it your own
Write a sentence using “smog”, then check it and compare it with the examples above.