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 laureates’ research has a vast array of real-world uses, and could provide a way to combat climate change by capturing carbon dioxide from the atmosphere. —Katie Hunt, CNN Money, 8 Oct. 2025

In 2024, carbon dioxide emissions in advanced economies dropped to their lowest level in 50 years. —Daniel Peck, ABC News, 8 Oct. 2025

This means a single hot spell in the Arctic is likely not enough to warm carbon dioxide-releasing microbes, but a warm season is a different story. —Irene Wright, Miami Herald, 7 Oct. 2025

Meeting that demand by burning fossil fuels such as coal and gas for electricity releases planet-warming gases including carbon dioxide and methane. —Sydney Lake, Fortune, 7 Oct. 2025

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