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 peroxide (audio) \ adjective

Examples of peroxide in a Sentence

Recent Examples on the Web: Noun Semi-permanent color also doesn't contain peroxide or ammonia—two ingredients found in most permanent varieties. Patricia Shannon, Southern Living, "How Long Does Semi-Permanent Hair Dye Last?," 12 Mar. 2021 Benzoyl peroxide is an acne-clearing ingredient most notable for diminishing bacteria and absorbing excess sebum. Chelsea Hall, Marie Claire, "Benzoyl Peroxide vs. Salicylic Acid: The Benefits, Differences, and Uses," 4 Mar. 2021 Pretty funny monologue — and Pete has gone back to the peroxide hair? Andy Hoglund,, "Saturday Night Live recap: Bridgerton star Regé-Jean Page hosts with musical guest Bad Bunny," 21 Feb. 2021 Gaga, a perennial blonde, stepped out today with her signature peroxide locks a new shade of dark brown. Christian Allaire, Vogue, "Lady Gaga Debuts a Dramatic Hair Transformation," 4 Mar. 2021 Benzoyl peroxide kills acne-causing bacteria, witch hazel helps refine pores, and aloe can soothe. Sarah Kinonen, Allure, "Allure Editors' 30 Favorite Beauty Products of All Time," 25 Feb. 2021 Benzoyl peroxide fights off the bacteria on your skin, which can cause breakouts. Bre Richey,, "Sustainable skincare products you should try for breakouts," 20 Feb. 2021 These whitening pens contain carbamide peroxide gel that’s directly applied to the teeth, designed to break down surface stains from foods and drink. Hanna Horvath, NBC News, "The best at-home teeth whitening products, according to dentists," 14 Jan. 2021 Strips are coated with either carbamide peroxide or hydrogen peroxide, both of which loosen and remove superficial staining -- without damaging teeth's enamel. Sian Babish,, "The best teeth whitening strip of 2020," 26 Sep. 2020 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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Time Traveler for peroxide

Time Traveler

The first known use of peroxide was in 1804

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Statistics for peroxide

Last Updated

19 Mar 2021

Cite this Entry

“Peroxide.” Dictionary, Merriam-Webster, Accessed 18 Apr. 2021.

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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

Nglish: Translation of peroxide for Spanish Speakers

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

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