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

This tiny trans-Neptunian object, meanwhile, has a remarkably precarious atmosphere perhaps composed of methane, nitrogen or carbon monoxide that is 5 to 10 million times thinner than Earth's, Reuters reported. —Eric Lagatta, USA Today, 6 May 2026

The Webb telescope also could detect methane or carbon monoxide emissions coming from the object and identify the atmosphere’s composition. —Ashley Strickland, CNN Money, 4 May 2026

The likeliest atmospheric chemicals are methane, nitrogen or carbon monoxide, any of which could reproduce the observed dimming as the object passed before the star, according to Arimatsu. —CBS News, 4 May 2026

Charcoal and gas grills both produce carbon monoxide, a colorless, odorless gas that can build up quickly and become deadly within minutes. —Jessica Safavimehr, Southern Living, 30 Apr. 2026

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