hydroxyl

American  

[hahy-drok-suhl] / haɪˈdrɒk səl /

Or hydroxy

adjective

1. containing the hydroxyl group.

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hydroxyl British  

/ haɪˈdrɒksɪl /

noun

1. (modifier) of, consisting of, or containing the monovalent group -OH or the ion OH ^–

   a hydroxyl group or radical

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hydroxyl Scientific  

/ hī-drŏk′sĭl /

1. The group OH. Hydroxyl is present in bases, certain acids, hydroxides, and alcohols.

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Other Word Forms

• hydroxylic
  adjective

Etymology

Origin of hydroxyl

First recorded in 1865–70; hydr- ² + ox(y)- ² + -yl

Compare meaning

How does hydroxyl compare to similar and commonly confused words? Explore the most common comparisons:

• hydroxyl vs. alcohol

Example Sentences

Swift detected hydroxyl when the comet was nearly three times farther from the Sun than Earth is, well beyond the region where surface ice would normally turn directly into vapor.

From Science Daily • Feb. 11, 2026

Throughout the process, Huml also uses a variety of machines to clean the air, including air scrubbers, deodorizing hydroxyl generators and negative air machines that clean the air and push it outside.

From Los Angeles Times • Jan. 16, 2025

This is because hydroxyl radicals form in the atmosphere close to the ground during the day when the sun shines.

From Science Daily • Dec. 4, 2024

It can result, above all, from the reaction of sulfur dioxide with hydroxyl radicals.

From Science Daily • Dec. 4, 2024

By transformations of the carbonyl group, and at the same time of the hydroxyl group, many interesting types of nitrogen compounds may be correlated.

From Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 1 "Châtelet" to "Chicago" by Various