impurity

noun

im·​pu·​ri·​ty (ˌ)im-ˈpyu̇r-ə-tē 

plural impurities

1

: something that is impure or makes something else impure

removing impurities from water

2

: the quality or state of being impure

Synonyms of impurity

• contamination
• contaminant
• pollutant

Examples of impurity in a Sentence

the impurity of the water

The syrup is strained to remove impurities.

The water is free of impurities.

Recent Examples on the Web

Seawater brings additional problems involving competing chlorine chemistry, catalysts, impurities, and deposits. — New Atlas, 3 Sep. 2026

Companies like Coca-Cola and Pepsi—who own Dasani and Aquafina, respectively—take tap water, treat it (which typically means removing some minerals deemed impurities), bottle it, and sell it at a markup. — Sam Stone, Bon Appetit Magazine, 27 Aug. 2026

That concentrate requires further refining to remove impurities. — Matthew Kayser, USA Today, 21 Aug. 2026

After 15 years of experiments, Schumm’s group ended up with a recipe for solid calcium fluoride crystals, doped with little impurities of thorium 229, that looked like transparent millimeter-sized cubes. — Jacek Krywko, Scientific American, 20 Aug. 2026

Word History

First Known Use

15th century, in the meaning defined at sense 1

Rhymes for impurity

• maturity
• obscurity
• security
• biosecurity
• cybersecurity
• immaturity
• insecurity
• prematurity
• purity
• surety

Kids Definition

impurity

noun

im·​pu·​ri·​ty (ˈ)im-ˈpyu̇r-ət-ē 

plural impurities

1

: the quality or state of being impure

2

: something that is impure or that makes impure

remove impurities from water

Medical Definition

impurity

noun

im·​pu·​ri·​ty (ˈ)im-ˈpyu̇r-ət-ē 

plural impurities

: something that is impure or makes something else impure