# oxide

/ˈɑkˌsaɪd/ (US) · /ˈɒksaɪd/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/oxide
Updated: 2026-05-03

## Definition

a chemical substance that forms when oxygen combines with another element. You might know it as rust when it happens to iron.

For teachers: a binary compound of oxygen with another element or group. Often used in technical contexts to describe the result of oxidation processes.

## Examples

- Iron oxide is the scientific name for rust.
- The chemist analyzed the white powder and identified it as zinc oxide, commonly used in sunscreens.
- Environmental regulations have become increasingly strict regarding the emission of nitrogen oxide from industrial plants due to its role in the formation of acid rain.

## Usage notes

- Uncountable when referring to the chemical substance in general; countable when referring to specific types or varieties of the compound.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.