What is the meaning of Peroxide?

A divalent radical or anion containing two oxygen atoms linked by a covalent bond; any substance containing this group yields hydrogen peroxide when treated with an acid.

Hydrogen peroxide, especially when in an aqueous solution used as a bleach.

Any compound containing the functional group R-O-O-R'.

To treat (something) with hydrogen peroxide, especially hair in order to bleach it.

peroxide

Source: wiktionary.org