Synonyms

carbon dioxide

American

[kahr-buhn dahy-ok-sahyd] / ˈkɑr bən daɪˈɒk saɪd /

noun

a colorless, odorless, incombustible gas, CO 2 , present in the atmosphere and formed during respiration, usually obtained from coal, coke, or natural gas by combustion, from carbohydrates by fermentation, by reaction of acid with limestone or other carbonates, or naturally from springs: used extensively in industry as dry ice, or carbon dioxide snow, in carbonated beverages, fire extinguishers, etc.

carbon dioxide British

noun

Also called: carbonic-acid gas. a colourless odourless incombustible gas present in the atmosphere and formed during respiration, the decomposition and combustion of organic compounds, and in the reaction of acids with carbonates: used in carbonated drinks, fire extinguishers, and as dry ice for refrigeration. Formula: CO 2

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

carbon dioxide Scientific

A colorless, odorless gas that is present in the atmosphere and is formed when any fuel containing carbon is burned. It is breathed out of an animal's lungs during respiration, is produced by the decay of organic matter, and is used by plants in photosynthesis. Carbon dioxide is also used in refrigeration, fire extinguishers, and carbonated drinks. Chemical formula: CO ₂ .

carbon dioxide Cultural

A compound made up of molecules containing one carbon atom and two oxygen atoms.

Discover More

Carbon dioxide is normally found as a gas that is breathed out by animals and absorbed by green plants. The plants, in turn, return oxygen to the atmosphere. (See carbon cycle and respiration.)

Carbon dioxide is also given off in the burning of fossil fuels (see greenhouse effect).

Etymology

Origin of carbon dioxide

First recorded in 1870–75

Compare meaning

How does carbon-dioxide compare to similar and commonly confused words? Explore the most common comparisons:

carbon monoxide vs. carbon dioxide

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Laboratory research has demonstrated that these compounds can form when icy dust grains containing methanol or blends of carbon dioxide and ammonia are exposed to ultraviolet light or gentle heating.

From Science Daily

That iron would fuel blooms of microscopic algae, which absorb heat trapping carbon dioxide as they grow.

From Science Daily

Power plant stacks emitted more sulfur dioxide, nitrogen oxide and carbon dioxide last year, according to an analysis of government data.

From The Wall Street Journal

First, environmental conditions during the Mesozoic were different, with warmer global temperatures and higher carbon dioxide levels.

From Science Daily

In terms of keeping buildings warm, heat pumps are widely seen as the best way of cutting emissions of carbon dioxide and helping to achieve net zero goals.

From BBC

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023