contaminated; contaminating
Synonyms of contaminate

transitive verb

1
a
: to soil, stain, corrupt, or infect by contact or association
Bacteria contaminated the wound.
b
: to make inferior or impure by admixture
iron contaminated with phosphorus
2
: to make unfit for use by the introduction of unwholesome or undesirable elements
water contaminated by sewage

Did you know?

Contaminate, taint, pollute, and defile mean to make impure or unclean. Contaminate implies intrusion of or contact with dirt or foulness from an outside source (logically enough, it derives from the Latin word tangere, meaning "to touch"). Taint stresses a loss of purity or cleanliness that follows contact ("tainted meat"). Pollute, sometimes interchangeable with contaminate, may imply that the process which begins with contamination is complete and that what was pure or clean has been made foul, poisoned, or filthy ("the polluted waters of the river"). Defile implies befouling of what could or should have been kept clean and pure or held sacred, and commonly suggests violation or desecration ("vandals defiled the mausoleum").

Choose the Right Synonym for contaminate

contaminate, taint, pollute, defile mean to make impure or unclean.

contaminate implies intrusion of or contact with dirt or foulness from an outside source.

water contaminated by industrial wastes

taint stresses the loss of purity or cleanliness that follows contamination.

tainted meat
a politician's tainted reputation

pollute, sometimes interchangeable with contaminate, distinctively may imply that the process which begins with contamination is complete and that what was pure or clean has been made foul, poisoned, or filthy.

the polluted waters of the river

defile implies befouling of what could or should have been kept clean and pure or held sacred and commonly suggests violation or desecration.

defile a hero's memory with slanderous innuendo

Examples of contaminate in a Sentence

Be careful not to allow bacteria to contaminate the wound. Don't touch the microchip or the oil on your hands will contaminate it. Make sure the white paint is not contaminated by any of the other colors.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
People become infected with the illness by consuming food or water that has been contaminated with the parasite — the infection is not transmitted from person to person. Karen Garcia, Los Angeles Times, 10 July 2026 The district, which plans to send out an inspector, could determine whether wind carrying coal dust stored nearby may be contaminating the sugar. Sierra Lopez, Mercury News, 9 July 2026 Symptoms can start any time between two and 14 days after consuming contaminated food or water. Devika Rao, TheWeek, 9 July 2026 The bacteria has contaminated a line that connects to an icemaker used by employees, according to the statement. Sofia Williams, Sacbee.com, 9 July 2026 See All Example Sentences for contaminate

Word History

Etymology

Middle English contaminaten, borrowed from Latin contāminātus, past participle of contāmināre "to defile, pollute," from con- con- + -tāmināre, verbal derivative of *tāmen "touching, contact," going back to *tāg-(s)men, from tag-, variant stem of tangere "to touch" + *-(s)men, noun suffix of result — more at tangent entry 2

First Known Use

15th century, in the meaning defined at sense 1a

Time Traveler
The first known use of contaminate was in the 15th century

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Cite this Entry

“Contaminate.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/contaminate. Accessed 10 Jul. 2026.

Kids Definition

contaminate

verb
contaminated; contaminating
1
: to soil, stain, or infect by contact or association
2
: to make impure or unfit for use by adding something harmful or unpleasant
wells contaminated by chemicals
contamination
-ˌtam-ə-ˈnā-shən
noun

Medical Definition

contaminate

transitive verb
contaminated; contaminating
1
: to soil, stain, or infect by contact or association
bacteria contaminated the wound
2
: to make unfit for use by the introduction of unwholesome or undesirable elements
water contaminated by sewage

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