meth·​yl ˈme-thəl How to pronounce methyl (audio)
: an alkyl radical CH3 derived from methane
methylic adjective

Examples of methyl in a Sentence

Recent Examples on the Web This is because almost all cases of Rett syndrome are caused by mutations found on an X chromosome gene called methyl CpG binding protein, or MECP2. William A. Haseltine, Forbes, 27 Feb. 2024 The methyl group acts like a tiny thumbtack set out on the seat the antibiotic was hoping to take, Polikanov said. Corinne Purtill, Los Angeles Times, 15 Feb. 2024 After all, if our methyl groups and coiling proteins were constantly shifting, depression would be the least of our problems. Carl Zimmer, Discover Magazine, 12 Apr. 2023 In this recent work, her lab generated an enzyme that can biodegrade volatile methyl siloxanes. Diana Gitig, Ars Technica, 5 Feb. 2024 Kohoutek also marked the first direct detection of methyl cyanide, hydrogen cyanide and silicates in a comet. Greg Daugherty, Smithsonian Magazine, 4 Dec. 2023 That idea began to unravel in 1994, when Low discovered that a chemical tag called a methyl group could block transcription in bacteria—something scientists had thought was exclusive to eukaryotic cells. Carrie Arnold, Scientific American, 30 Mar. 2022 For example, instead of using folic acid, which can be difficult for some individuals to process, Ritual uses a form of folate called methyl folate that is easier for the body to utilize. Amber Smith, Discover Magazine, 13 Aug. 2023 The carbon compound is known as methyl cation, or CH3+. Julia Musto, Fox News, 29 June 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'methyl.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


International Scientific Vocabulary, back-formation from methylene

First Known Use

1840, in the meaning defined above

Time Traveler
The first known use of methyl was in 1840

Dictionary Entries Near methyl

Cite this Entry

“Methyl.” Dictionary, Merriam-Webster, Accessed 23 Jun. 2024.

Kids Definition


meth·​yl ˈmeth-əl How to pronounce methyl (audio)
: a chemical group consisting of carbon and hydrogen

Medical Definition


ˈmeth-əl, British also ˈmē-ˌthīl
: an alkyl group CH3 that is derived from methane by removal of one hydrogen atom
methylic adjective

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