hydroxyl

American  

[hahy-drok-suhl] / haɪˈdrɒk səl /

Or hydroxy

adjective

1. containing the hydroxyl group.

---

hydroxyl British  

/ haɪˈdrɒksɪl /

noun

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

   a hydroxyl group or radical

---

hydroxyl Scientific  

/ hī-drŏk′sĭl /

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

---

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

This structure is capable of producing both hydroxyl radicals and singlet oxygen, increasing its cancer-fighting potential.

From Science Daily • Mar. 1, 2026

One of the biggest drivers was a sharp drop in hydroxyl radicals, which are the main chemicals responsible for breaking methane down in the air.

From Science Daily • Feb. 10, 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

Due to the geometry of the feldspar crystal, these hydroxyl groups are positioned in a way that makes them ideal anchoring points for water molecules.

From Science Daily • Jan. 9, 2024

But since water is almost entirely undissociated, equilibrium can only be reached when there are very few hydroxyl or hydrogen ions present.

From An Elementary Study of Chemistry by McPherson, William