hydroxyl
noun
hy·drox·yl
hī-ˈdräk-səl 
1
: the chemical group, ion, or radical OH that consists of one atom of hydrogen and one of oxygen and is neutral or negatively charged
Examples of hydroxyl in a Sentence
Recent Examples on the Web
Lightning also sparks hydroxyl radicals, which help cleanse the air by breaking down methane and other gases.
—
Aamir Khollam, Interesting Engineering, 29 Aug. 2025
During photocatalysis, light is absorbed by photocatalysts that have the ability to create electron-hole pairs, which generate free hydroxyl radicals that are able to react with target pollutants and degrade them.
—IEEE Spectrum, 23 Jan. 2023
More proof: Glycerin, one of the best moisturizers available, is a polyol, a type of alcohol with multiple hydroxyl groups.
—Elizabeth Siegel, Allure, 26 Sep. 2022
After each lightning flash, the researchers found the concentrations of hydroxyl and hydroperoxyl increased by thousands of parts per trillion, Science News reports.
—Elizabeth Gamillo, Smithsonian Magazine, 4 May 2021
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Aamir Khollam, Interesting Engineering, 29 Aug. 2025
During photocatalysis, light is absorbed by photocatalysts that have the ability to create electron-hole pairs, which generate free hydroxyl radicals that are able to react with target pollutants and degrade them.
—IEEE Spectrum, 23 Jan. 2023
More proof: Glycerin, one of the best moisturizers available, is a polyol, a type of alcohol with multiple hydroxyl groups.
—Elizabeth Siegel, Allure, 26 Sep. 2022
After each lightning flash, the researchers found the concentrations of hydroxyl and hydroperoxyl increased by thousands of parts per trillion, Science News reports.
—Elizabeth Gamillo, Smithsonian Magazine, 4 May 2021
See All Example Sentences for hydroxyl
Cite this Entry
“Hydroxyl.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hydroxyl. Accessed 10 Sep. 2025.
Copy CitationKids Definition
hydroxyl
noun
hy·drox·yl
hī-ˈdräk-səl
: a chemical group or ion that consists of one atom of hydrogen and one of oxygen
Medical Definition
hydroxyl
noun
hy·drox·yl
hī-ˈdräk-səl
1
: the chemical group or ion OH that consists of one atom of hydrogen and one of oxygen and is neutral or positively charged
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