carbon monoxide

noun

: a colorless odorless very toxic gas CO that is formed as a product of the incomplete combustion of carbon or a carbon compound

Examples of carbon monoxide in a Sentence

Recent Examples on the Web

During the late 19th and early 20th century, coal miners in Europe and North America used canaries as living carbon monoxide alarms. —Big Think, 13 Oct. 2025

For light cleaning, technicians sometimes spray frozen carbon monoxide across the surface to dislodge the dust. —Kenna Hughes-Castleberry, Space.com, 6 Oct. 2025

Signs of carbon monoxide poisoning include headache, dizziness, vomiting, chest pain and weakness. —Mike Stunson, Kansas City Star, 24 Sep. 2025

Monday’s lawsuit says the Food and Drug Administration has approved hyperbaric oxygen treatment for 13 conditions, such as carbon monoxide poisoning, foot wounds related to diabetes and decompression sickness in divers. —Elizabeth Chuck, NBC news, 22 Sep. 2025

Word History

First Known Use

1868, in the meaning defined above

Rhymes for carbon monoxide

• hydroxide
• tetroxide

Kids Definition

carbon monoxide

noun

: a colorless odorless very poisonous gas formed by the incomplete burning of carbon

Medical Definition

carbon monoxide

noun

: a colorless odorless very toxic gas CO that burns to carbon dioxide with a blue flame and is formed as a product of the incomplete combustion of carbon