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

The second source of unwanted immune response is impurities from mRNA production. — Li Li, The Conversation, 6 Aug. 2026

To break through the water’s tight molecular network, the escaping CO2 relies on nucleation sites—microscopic rough spots, impurities, or foreign objects that disrupt the arrangement of water molecules and allow gas molecules to easily cluster. — Encyclopedia Britannica, 5 Aug. 2026

But impurities can be scattered throughout the array, including the incorporation of nitrogen. — ArsTechnica, 29 July 2026

Cleaning vinegar is too strong to be used in cooking and may contain impurities that aren’t safe for consumption. — Brandee Gruener, Southern Living, 23 July 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