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

The roughly 70 million metric tons of aluminum produced each year generate about 3% of global industrial carbon dioxide emissions. — Richard Eisenberg, Time, 15 Oct. 2026

What early concrete evangelists didn’t realize was that the modern way of producing the substance released giant amounts of carbon dioxide into the atmosphere. — Sara Herschander, Vox, 15 Oct. 2026

Globally, ocean temperatures also reached new heights in July, the report said, while data show that carbon dioxide levels in the atmosphere are higher now than at any other time in the last 2 million years. — Emily Mae Czachor, CBS News, 14 Oct. 2026

Leaves contain pores called stomata, which take carbon dioxide in and let water out. — Devika Rao, TheWeek, 13 Oct. 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