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

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 For it, Gaga still rocks her peroxide-blonde hair and dark, feathered brows. Leah Prinzivalli, Allure, "Lady Gaga's Minimalist Look for Vogue's October Cover Was Done With Just $50 of Drugstore Makeup," 10 Sep. 2018 Without those generators, the organic peroxides made at the plant grew unstable and ultimately ignited, spreading noxious smoke for miles. Erin Ailworth, WSJ, "Texas Grand Jury Indicts Chemical Company for Harvey Explosion," 3 Aug. 2018 When a harvest is finished, replace the rock wool and clean the system's reservoir, pump, and tubing with a 3 percent hydrogen-peroxide solution. Daniel Kluko, Popular Mechanics, "How to Grow Hydroponic Plants at Home," 13 Feb. 2017 The California native took on a British accent, and his brown hair was crisped and brightened with peroxide. Andrew Dansby, Houston Chronicle, "‘Buffy’ vampire James Marsters comes out in the daylight for Comicpalooza," 23 May 2018 For those who wear their contact lenses for a couple of weeks or a month, Haberman says that peroxide solutions, like ClearCare, will help reduce the risk of infection. Katie Heaney, The Cut, "Are My Contacts Going to Make Me Go Blind?," 11 July 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

15 Feb 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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