What does oxidised mean?
Oxidised means changed chemically through the addition of oxygen or through a related reaction. The term is especially common when describing iron that has rusted, copper that has developed a green patina, or silver that has tarnished. In technical writing, it refers to a chemical process rather than simply a dirty or damaged surface. The word is most naturally used with materials and surfaces: an oxidised metal, an oxidised layer, or an oxidised finish. Its everyday associations include age, corrosion, and exposure to air or moisture, although oxidation can also produce useful and attractive surface layers. In British English the standard spelling is oxidised, while American English generally uses oxidized.
Chemically altered by oxidation; in everyday contexts, rusted, tarnished, or covered with a patina.
"The oxidised iron produced a deep reddish-brown colour."
Common in technical, scientific, and descriptive writing about metals and other materials.
The past tense and past participle of oxidise: to undergo oxidation or to cause something to undergo oxidation.
"Heat oxidised the iron and changed its surface."
The spelling is British; American English uses oxidized.
Oxidised metal is not merely dirty: its surface has been chemically transformed by oxygen.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does oxidised come from?
The word comes from the Latin oxidare, meaning “to make sharp” or “to make into acid,” and from the related Greek oxys, meaning “sharp” or “acid.” Its modern chemical sense developed during the nineteenth century as scientists described reactions involving oxygen. Oxidise and oxidised belong to a family that includes oxide, oxidation, and oxygen, all reflecting the same chemical root.
Related word forms
How oxidised is actually used
The word is formal or technical in general use, though it is also common in descriptions of rusted or tarnished metal. British English usually spells it with an s, while American English spells it with a z.
Easily confused with oxidised
Oxidise is the British spelling of the base verb, while oxidised is its past-tense and past-participle form.