hydroxyl

noun

hy·​drox·​yl hī-ˈdräk-səl How to pronounce hydroxyl (audio)
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
2
: hydroxide sense 1
hydroxylic
ˌhī-ˌdräk-ˈsi-lik How to pronounce hydroxyl (audio)
adjective

Examples of hydroxyl 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.
Fixing the problem Flexible substrates have uneven surface roughness and varying hydroxyl-group densities, making standard large-area printing techniques ineffective. — Mrigakshi Dixit, Interesting Engineering, 26 Oct. 2026 Water essentially acts as a catalyst that spontaneously creates particles known as hydroxyl radicals, unstable molecules linked to aging and disease. — Michael Hawthorne, Chicago Tribune, 22 Oct. 2026 The polystyrene powder and water mixture contained hydroxyl radicals, a highly reactive ROS. — Jacek Krywko, ArsTechnica, 15 Oct. 2026 Fluorine is then released into the water as fluoride ions, while hydroxyl radicals and hydroxide ions help sever carbon-carbon bonds in the remaining molecular chains. — Alexandra Harrell, Footwear News, 14 Oct. 2026 See All Example Sentences for hydroxyl

Word History

Etymology

hydr- + ox- + -yl

First Known Use

1869, in the meaning defined at sense 1

Time Traveler
The first known use of hydroxyl was in 1869

Rhymes for hydroxyl

See All Rhymes for hydroxyl

Browse Nearby Words

hydroxy ketone
hydroxyl
hydroxylamine
See all Nearby Words

Cite this Entry

“Hydroxyl.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hydroxyl. Accessed 1 Nov. 2026.

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Kids Definition

hydroxyl

noun
hy·​drox·​yl hī-ˈdräk-səl How to pronounce hydroxyl (audio)
: 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 How to pronounce hydroxyl (audio)
1
: the chemical group or ion OH that consists of one atom of hydrogen and one of oxygen and is neutral or positively charged
2
: hydroxide sense 1
hydroxylic
ˌhī-ˌdräk-ˈsil-ik How to pronounce hydroxyl (audio)
adjective
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