Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English


English definition of “carbon monoxide”

carbon monoxide

noun [U]    
ENVIRONMENT a poisonous gas formed when carbon is not burned completely , produced by vehicles and by heating equipment that is not working properly : carbon monoxide poisoning /buildup/ exposure
→ Compare carbon dioxide
(Definition of carbon monoxide noun from the Cambridge Business English Dictionary © Cambridge University Press)
Focus on the pronunciation of carbon monoxide

Definitions of “carbon monoxide” in other dictionaries

Word of the Day


relating to behaviour between people that is pleasant and friendly, often despite a difficult situation

Word of the Day


Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More