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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Carbon Monoxide and Smoke Detectors Nearly every homeowner recognizes the incessant chirp that indicates a dying battery in a carbon monoxide or smoke detector, but few know that the units themselves should be replaced after 7 to 10 years. — Kamron Sanders, Better Homes & Gardens, 27 Sep. 2026 When thermal runaway starts, the process can continue for days, with the potential for batteries to release toxic gases such as hydrogen fluoride, hydrogen chloride and carbon monoxide. — Clara Harter, Los Angeles Times, 25 Sep. 2026 Breaking the dependency loop For people trying to quit vaping, health providers warn that switching to cigarettes reintroduces harmful toxins, tar and carbon monoxide. — Khloe Quill, FOXNews.com, 24 Sep. 2026 The greatest health risks arise when tobacco is burned, which generates thousands of toxic substances, including carcinogens, carbon monoxide and fine particulate matter. — Hasmeena Kathuria, The Conversation, 22 Sep. 2026 See All Example Sentences for carbon monoxide

Word History

First Known Use

1868, in the meaning defined above

Time Traveler
The first known use of carbon monoxide was in 1868

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Cite this Entry

“Carbon monoxide.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/carbon%20monoxide. Accessed 3 Oct. 2026.

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

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