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

Method 2 Using a clean cloth, soak a corner in hydrogen peroxide. —Mary Catherine McAnnally Scott, Southern Living, 6 Feb. 2025

When researchers exposed tardigrades to the extreme cold, or things like sugar, salt or hydrogen peroxide, the animals began to produce free radicals, or oxygen atoms with an extra electron. —Carlyn Kranking, Smithsonian Magazine, 31 Dec. 2024

If there are some really tough spots, add hydrogen peroxide to your baking soda paste. —Cody Godwin, USA TODAY, 23 Jan. 2025

If your cast iron, ceramic, or porcelain sink has deep discoloration, combine baking soda with hydrogen peroxide instead of water for a more powerful clean. —Mary Cornetta, Better Homes & Gardens, 29 Oct. 2024

Word History

First Known Use

1872, in the meaning defined above

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