# impurity

/ˌɪmˈpjʊɹəti/ (US) · /ɪmpjˈʊɹɪti/ (UK) · CEFR B2 · Noun

Source: https://englishreference.com/word/impurity
Updated: 2026-06-22

## Definition

a small amount of something that is not pure. It can be a dirt particle in water or a bad quality in a person's character.

For teachers: a substance that is not pure; an element or compound that is present in a material in an undesired or unintended state. Often used metaphorically to describe a flaw in a person's character or a process.

## Examples

- The water was clear, but it still contained a small impurity.
- The chemist used a special filter to remove any impurity from the liquid before the final test.
- While the diamond was nearly flawless, a microscopic impurity in the crystal lattice caused it to refract light in a slightly different way than a pure specimen.

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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.