contaminate

verb

con·​tam·​i·​nate kən-ˈta-mə-ˌnāt How to pronounce contaminate (audio)
contaminated; contaminating

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
contaminative adjective
contaminator noun

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.
Less clear is the cancer-causing potential of talc when it’s not contaminated. Matt Fuchs, Time, 23 July 2025 The material, which is not contaminated, is being redeposited in nearby bird sanctuaries and new islands formed within the lake system. Nolan McKendry, The Washington Examiner, 20 July 2025 Although the bacterium can contaminate many types of food, cheeses or deli meats that are kept in cold storage for long periods in stores or at home are a place where listeria can keep growing. Matthew Robinson, MSNBC Newsweek, 18 July 2025 Consumption of or contact with water contaminated with feces of warm-blooded animals can cause a variety of illnesses, the U.S. Geological Survey said. Jalen Williams, Freep.com, 18 July 2025 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 26 Jul. 2025.

Kids Definition

contaminate

verb
con·​tam·​i·​nate kən-ˈtam-ə-ˌnāt How to pronounce contaminate (audio)
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
contaminator noun

Medical Definition

contaminate

transitive verb
con·​tam·​i·​nate kən-ˈtam-ə-ˌnāt How to pronounce contaminate (audio)
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
contaminative adjective
contaminator noun

More from Merriam-Webster on contaminate

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