hydroxide

noun

hy·​drox·​ide hī-ˈdräk-ˌsīd 

1

: the monovalent anion OH⁻ consisting of one atom of hydrogen and one of oxygen

called also hydroxide ion

2

: an ionic compound of hydroxide with an element or group

Examples of hydroxide in a Sentence

Recent Examples on the Web

Then, a simple water-splitting reaction at the auxiliary electrode generates hydroxide, which combines with the lithium to produce lithium hydroxide. —New Atlas, 31 Dec. 2025

Laboratory work has shown that ice naturally contains ionic defects—hydronium (H₃O⁺) and hydroxide (OH⁻) ions. —Tejasri Gururaj, Interesting Engineering, 30 Dec. 2025

Antacids generally contain aluminum hydroxide, calcium carbonate, sodium bicarbonate, or bismuth subsalicylate. —Ann Pietrangelo, Verywell Health, 4 Sep. 2025

The new high-pressure acid leaching smelter will produce 66,000 tons of nickel in mixed hydroxide precipitate each year when completed, using nickel ore from Vale Indonesia’s mines. —Yessar Rosendar, Forbes.com, 28 Aug. 2025

Word History

Etymology

International Scientific Vocabulary

First Known Use

1851, in the meaning defined at sense 1

Phrases Containing hydroxide

• ammonium hydroxide
• calcium hydroxide
• magnesium hydroxide
• potassium hydroxide
• sodium hydroxide

Rhymes for hydroxide

• monoxide
• tetroxide

Kids Definition

hydroxide

noun

hy·​drox·​ide hī-ˈdräk-ˌsīd 

: a negatively charged ion consisting of one atom of oxygen and one atom of hydrogen

Medical Definition

hydroxide

noun

hy·​drox·​ide hī-ˈdräk-ˌsīd 

1

: the monovalent anion OH⁻ consisting of one atom of hydrogen and one of oxygen

called also hydroxide ion

2

: an ionic compound of hydroxide with an element or group