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

Burning natural gas generates carbon dioxide, which is the main driver of climate change. — Ashwini Sehgal, The Conversation, 23 July 2026

Using precious metals and chemical reactions, catalytic converters transform harmful carbon monoxide, hydrocarbons and nitrogen oxides into significantly less harmful carbon dioxide, nitrogen and water vapor. — Peter Lyon, Forbes.com, 22 July 2026

HFCs, a potent category of greenhouse gas used for refrigeration and cooling, can have an impact on global warming that is thousands of times greater than the equivalent amount of carbon dioxide. — Alula Alderson, Sacbee.com, 21 July 2026

Even planets that lose their initial atmospheres entirely — instead of gradually replacing them with things like carbon dioxide and methane — might have a second chance to build a new atmosphere. — Kiona N. Smith, Space.com, 21 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