per·​ox·​ide | \ pə-ˈräk-ˌsīd How to pronounce peroxide (audio) \

Definition of peroxide

 (Entry 1 of 3)

: a compound (such as hydrogen peroxide) in which oxygen is visualized as joined to oxygen


peroxided; peroxiding

Definition of peroxide (Entry 2 of 3)

transitive verb

: to treat with a peroxide especially : to bleach (hair) with hydrogen peroxide



Definition of peroxide (Entry 3 of 3)

: having or being bleached hair a peroxide blonde

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Other Words from peroxide


peroxidic \ pə-​ˌräk-​ˈsi-​dik How to pronounce peroxidic (audio) \ adjective

Examples of peroxide in a Sentence

Recent Examples on the Web: Noun

Roxette’s cyber-avatar, a peroxide-blond ninja, is played by Pom Klementieff; Lance is an athletic karate expert played by Ludi Lin. David Sims, The Atlantic, "Black Mirror: The Weird, Intriguing Intimacy of ‘Striking Vipers’," 5 June 2019 Those investigations led to a discovery a couple of years later involving the reactive oxygen species (ROS) — unstable molecules containing oxygen, such as peroxides, singlet oxygen and hydroxyl radicals — that mitochondria release while making ATP. Quanta Magazine, "Biologists Discover Unknown Powers in Mighty Mitochondria," 18 Mar. 2019 Islamic State provided him with several thousand dollars, as well as instructions on how to build a peroxide bomb. Daniel Byman, WSJ, "When Jihadists Come Back Home," 23 May 2019 Next, mix up a thin paste of 1 tablespoon baking soda and ½ tablespoon each of hydrogen peroxide and warm water. Dip an old toothbrush or soft brush into to the baking soda/peroxide paste and gently scrub your shoes. Carolyn Forte, Good Housekeeping, "How to Clean White Vans so They Look Brand New," 17 May 2019 Common ingredients include stain removers (such as sodium tripolyphosphateor hexametaphosphate and hydrated silica) and bleach, often listed as calcium peroxide or hydrogen peroxide. Joanne Chen, Redbook, "Teeth: An Owner's Manual," 24 July 2017 In celebration of her 21st birthday, Jenner ditched her bombshell onyx mane for lengths hued peroxide, which morphed from an interminable ponytail to an abbreviated iteration—a chic move reminiscent of older sister Kim Kardashian West. Calin Van Paris, Vogue, "Kylie Jenner Makes the Case for Growing Out Your Roots," 22 Aug. 2018 From peroxide dye jobs to choppy brunette pixies, Kristen Stewart knows a thing or two about dramatic hair transformations. Jenna Rennert, Vogue, "Kristen Stewart Updates Her Rock ’n’ Roll Pixie With a Surprising Twist," 16 Jan. 2019 At 25 percent carbamide peroxide, this CVS brand whitening kit hits near the top of the allowable range. Emma Sarran Webster, Allure, "6 of the Best Teeth-Whitening Kits in the Drugstore," 13 Sep. 2018

Recent Examples on the Web: Verb

Freshly peroxided, Mock headed to the skatepark later that day. Lauren Valenti, Vogue, "How This Skateboarder’s Radical Pink Buzz Cut Caught Frank Ocean’s Attention," 4 Feb. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'peroxide.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of peroxide


1804, in the meaning defined above


1899, in the meaning defined above


1899, in the meaning defined above

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Statistics for peroxide

Last Updated

21 Jun 2019

Look-up Popularity

Time Traveler for peroxide

The first known use of peroxide was in 1804

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More Definitions for peroxide



English Language Learners Definition of peroxide

: a chemical that is used chiefly to kill bacteria or to make hair lighter in color


per·​ox·​ide | \ pə-ˈräk-ˌsīd How to pronounce peroxide (audio) \

Kids Definition of peroxide


per·​ox·​ide | \ pə-ˈräk-ˌsīd How to pronounce peroxide (audio) \

Medical Definition of peroxide

: a compound (as hydrogen peroxide) in which oxygen is visualized as joined to oxygen

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More from Merriam-Webster on peroxide

Spanish Central: Translation of peroxide

Nglish: Translation of peroxide for Spanish Speakers

Britannica English: Translation of peroxide for Arabic Speakers Encyclopedia article about peroxide

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