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

According to the research team, the technology could prevent about 500 million metric tons of carbon dioxide pollution annually. — Georgina Jedikovska, Interesting Engineering, 7 Aug. 2026

The country has set a 10 million metric ton (11,023,113 ton) carbon dioxide equivalent budget for international carbon market transactions up to 2030. — ABC News, 4 Aug. 2026

Some programs investigate complaints by setting small surveillance traps—often baited with light, carbon dioxide, water, or another attractant—to collect mosquitoes, identify the species, and gauge where activity is concentrated. — Angela Haupt, Time, 3 Aug. 2026

Idling of vehicles with engines that burn fossil fuels also emits climate-warming greenhouse gases like carbon dioxide, though climate concerns are not the primary target of anti-idling laws. — Richard Marcantonio, The Conversation, 31 July 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