acid rain

American  

[as-id reyn] / ˈæs ɪd ˈreɪn /

noun

1. precipitation, as rain, snow, or sleet, containing relatively high concentrations of acid-forming chemicals, as the pollutants from coal smoke, chemical manufacturing, and smelting, that have been released into the atmosphere and combined with water vapor: harmful to the environment.

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acid rain British  

noun

1. rain that contains a high concentration of pollutants, chiefly sulphur dioxide and nitrogen oxide, released into the atmosphere by the burning of fossil fuels such as coal or oil

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acid rain Cultural  

1. A type of precipitation made up of dilute acids, primarily a by-product of heavy industry.

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Discover More

Acid rain is a result of the combination of water with chemicals released into the atmosphere by the burning of fossil fuels.

Etymology

Origin of acid rain

First recorded in 1855–60

Example Sentences

The Clean Air Act required the use of cleaner coal and technology to remove pollutants to prevent acid rain and other harms.

From The Wall Street Journal • Feb. 26, 2026

Environmental Protection Agency is through the Clean Air Act, which does regulate sulfur dioxide as a pollutant and as a contributor to acid rain.

From Salon • Dec. 12, 2024

Part of the reason for concern is that when sulfur dioxide leaves the stratosphere and sinks into the lower atmosphere, it can potentially fall as acid rain.

From Los Angeles Times • Apr. 22, 2024

He was also passionate about environmental causes, leading a global treaty to protect the ozone layer and signing a pact with the U.S. to reduce the pollution that causes acid rain.

From Seattle Times • Mar. 5, 2024

Oh, and by the way, the loons are disappearing everywhere because their lakes are dying from acid rain.

From "A Walk in the Woods" by Bill Bryson

Related Words

• carbon dioxide
• fog
• smoke
• soot