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

Techouse says the technology could help offshore operators reduce fuel consumption and cut carbon dioxide emissions by up to 25% compared with conventional gas-turbine power generation. — Kaif Shaikh, Interesting Engineering, 19 Aug. 2026

For years, most machines that pull carbon dioxide out of ambient air, known as direct air capture (DAC) systems, have relied on steam for heat. — Emily Waltz, IEEE Spectrum, 19 Aug. 2026

Their combined annual emissions may be as high as 45 million metric tons of carbon dioxide equivalent, according to regulatory filings. — Matt Day, Fortune, 18 Aug. 2026

Power plant operators who’ve purchased an allowance may emit that amount of carbon dioxide — or sell portions of the allowance to other plants. — John Moritz, Hartford Courant, 18 Aug. 2026

Word History

First Known Use

1867, in the meaning defined above

Rhymes for carbon dioxide

• acetamide
• acetonide
• acidified
• antimonide
• beatified
• benzaldehyde
• borohydride
• chalcogenide
• commodified
• decalcified
• declassified
• disaccharide

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