carbon dioxide

noun

: a heavy colorless gas CO2 that does not support combustion, dissolves in water to form carbonic acid, is formed especially in animal respiration and in the decay or combustion of animal and vegetable matter, is absorbed from the air by plants in photosynthesis, and is used in the carbonation of beverages

Examples of carbon dioxide in a Sentence

Recent Examples on the Web
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The 2022 effort to transition the state fleet to electric was codified as part of Senate Bill 4, one of a series of bills passed by lawmakers and signed by Gov. Ned Lamont that year to set Connecticut on a path toward dramatically lowering emissions of carbon dioxide and other greenhouse gases. John Moritz, Hartford Courant, 14 Feb. 2025 Chlorophyll is necessary for photosynthesis, the process that takes carbon and oxygen from carbon dioxide and hydrogen from water to make carbohydrate, a plant’s energy source. Joshua Siskin, Orange County Register, 14 Feb. 2025 As a result of the strong growth in low-carbon energy sources, the IEA said, global emissions of carbon dioxide from the electricity sector are expected to plateau in the coming three years. Josh Hammer, Newsweek, 14 Feb. 2025 These twilight clouds, which are made of carbon dioxide ice — otherwise known as dry ice — can be seen at the top of the new images. Sharmila Kuthunur, Space.com, 13 Feb. 2025 See all Example Sentences for carbon dioxide 

Word History

First Known Use

1867, in the meaning defined above

Time Traveler
The first known use of carbon dioxide was in 1867

Dictionary Entries Near carbon dioxide

Cite this Entry

“Carbon dioxide.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/carbon%20dioxide. Accessed 21 Feb. 2025.

Kids Definition

carbon dioxide

noun
: a heavy colorless gas CO2 that is formed especially by the burning and breaking down of organic substances (as in animal respiration), is absorbed from the air by plants in photosynthesis, and has many industrial uses

Medical Definition

carbon dioxide

noun
: a heavy colorless gas CO2 that does not support combustion, dissolves in water to form carbonic acid, is formed especially in animal respiration and in the decay or combustion of animal and vegetable matter, is absorbed from the air by plants in photosynthesis, and is used in the carbonation of beverages

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