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

On Friday, Gilliam was on an ECMO machine, a heart-lung bypass system that removes carbon dioxide from the blood and sends oxygen-rich blood back to the body, while allowing the heart and lungs to rest, according to the Mayo Clinic. —Martha Ross, Mercury News, 3 Apr. 2026

Court documents claim that no one informed Johnson of the dangers of the substance, which is the solid form of carbon dioxide. —Chicago Tribune, 2 Apr. 2026

Brookhaven officials say trees play a critical role beyond aesthetics — helping produce oxygen, reduce carbon dioxide and other pollutants, and regulate temperatures in urban areas. —Zachary Bynum, CBS News, 2 Apr. 2026

That region is critical for detecting gases like carbon dioxide and methane. —Aamir Khollam, Interesting Engineering, 2 Apr. 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