peroxide

American  

[puh-rok-sahyd] / pəˈrɒk saɪd /

noun

1. Chemistry.

   1. hydrogen peroxide, H 2 O 2 or H–O–O–H.

   2. a compound containing the bivalent group –O 2 –, derived from hydrogen peroxide, as sodium peroxide, Na 2 O 2 , or dimethyl peroxide, C 3 H 6 O 2 .

   3. the oxide of an element that contains an unusually large amount of oxygen.

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verb (used with object)

peroxided, peroxiding

1. to use peroxide as a bleaching agent on (especially the hair).

peroxide British  

/ pəˈrɒksaɪd /

noun

1. short for hydrogen peroxide, esp when used for bleaching hair

2. any of a class of metallic oxides, such as sodium peroxide, Na 2 O 2 , that contain the divalent ion ^– O-O ^–

3. (not in technical usage) any of certain dioxides, such as manganese peroxide, MnO 2 , that resemble peroxides in their formula but do not contain the ^– O-O ^– ion

4. any of a class of organic compounds whose molecules contain two oxygen atoms bound together. They tend to be explosive

5. (modifier) of, relating to, bleached with, or resembling peroxide

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verb

1. (tr) to bleach (the hair) with peroxide

peroxide Scientific  

/ pə-rŏk′sīd′ /

1. A compound containing the group O ₂. Peroxides are strong oxidizers and are used as industrial bleaches. When any peroxide is combined with an acid, one of the products is hydrogen peroxide.

2. Hydrogen peroxide.

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Other Word Forms

• peroxidic
  adjective

Etymology

Origin of peroxide

First recorded in 1795–1805; per- + oxide

Example Sentences

And the unique printing process of Bonnie Ralston, shown by Arts Gowanus, uses found metal objects, salt, vinegar and hydrogen peroxide to create ghostly industrial prints out of corrosion.

From The Wall Street Journal • Apr. 10, 2026

The spinning crystals may help the parasite safely break down excess peroxide, reducing the risk of damage from harmful chemical reactions.

From Science Daily • Mar. 19, 2026

"We think that the breakdown of hydrogen peroxide likely makes an important contribution to reducing cellular stress," Sigala says.

From Science Daily • Mar. 19, 2026

When parasites were grown under low-oxygen conditions, which reduces hydrogen peroxide production, the crystals slowed to about half their usual speed, despite the parasites otherwise remaining healthy.

From Science Daily • Mar. 19, 2026

Hazel had a flash of a memory—Jack’s mom standing in front of her on some long-ago summer day, gently putting peroxide on a badly skinned knee, wincing along with Hazel.

From "Breadcrumbs" by Anne Ursu

Related Words

• lighten