hydrogen peroxide

noun

: an unstable compound H₂O₂ used especially as an oxidizing and bleaching agent, an antiseptic, and a propellant

Examples of hydrogen peroxide in a Sentence

Recent Examples on the Web

This, in turn, created chemical reactions that generated reactive oxygen species (ROS) – oxygen-containing molecules, such as hydrogen peroxide, that readily react with other substances thanks to unstable electrons. —New Atlas, 27 Jan. 2026

Clean mild stains with vinegar and water, mold stains with one part bleach to three parts water, and deep stains with hydrogen peroxide to help remove some of the discoloration. —Timothy Dale, The Spruce, 27 Jan. 2026

Oxygen bleach stain removers rely on hydrogen peroxide to lift stains and come in liquid or powder form. —Brandee Gruener, Southern Living, 26 Jan. 2026

The hydrogen peroxide formula is designed to be gentle, a key reason this kit is often tolerated well by those prone to sensitivity. —Jailynn Taylor, Allure, 17 Jan. 2026

Word History

First Known Use

1872, in the meaning defined above

Rhymes for hydrogen peroxide

• aminoglycoside
• chlordiazepoxide
• dimethylformamide
• oligosaccharide
• paraformaldehyde
• polynucleotide
• ribonucleotide
• abide
• allied
• applied
• aside
• astride

Kids Definition

hydrogen peroxide

noun

: an unstable liquid compound containing hydrogen and oxygen and used especially for bleaching and as an antiseptic

Medical Definition

hydrogen peroxide

noun

: an unstable compound H₂O₂ used especially as an oxidizing and bleaching agent and as an antiseptic