tox·​in | \ ˈtäk-sən How to pronounce toxin (audio) \

Definition of toxin

: a poisonous substance that is a specific product of the metabolic activities of a living organism and is usually very unstable, notably toxic when introduced into the tissues, and typically capable of inducing antibody formation

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Synonyms for toxin


bane, poison, toxic, venom

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Toxins Are Often Found in Nature

Long before chemists started creating poisons from scratch, humans were employing natural toxins for killing weeds and insects. For centuries South American tribes have used the toxin curare, extracted from a native vine, to tip their arrows. The garden flower called wolfsbane or monkshood is the source of aconite, an extremely potent toxin. The common flower known as jimsonweed contains the deadly poison scopolamine. And the castor-oil plant yields the almost unbelievably poisonous toxin called ricin. Today we hear health advisers of all kinds talk about ridding the body of toxins; but they're usually pretty vague about which ones they mean, and most of these "toxins" wouldn't be called that by biologists.

Examples of toxin in a Sentence

the toxin in scorpion venom read a pamphlet on the toxin responsible for botulism, a food poisoning that can cause paralysis and even death in some cases

Recent Examples on the Web

NewsCalifornia Senate passes bill to create banks for pot businesses The rules allow sales of cannabis that have been lab-tested for quality and have proven to be free of pesticides, chemicals and toxins. Peter Fimrite,, "Cheap cannabis products available before new California rules kick in," 27 June 2018 Poor diet, environmental toxins and stress contribute to inflammatory processes. Maria Conley, Detroit Free Press, "Inflammation and your diet: What’s the connection?," 4 June 2018 To continue reading this story, TRY IT NOW Gulf War Veterans are also pressing the VA to compensate them for exposure to nerve agents and other toxins. Bill Lambrecht, San Antonio Express-News, "Congress considering benefits for Navy vets with Agent Orange exposure," 2 June 2018 Testing has since deemed the public water supply unaffected, but a report last spring by the utility showed a connection between the shallow aquifer where toxins were found and the deeper Memphis Sand Aquifer that provides the city’s drinking water. Jonathan Mattise, The Seattle Times, "New TVA head says board right on coal plant closures," 12 Apr. 2019 No toxins have been found, a virus was thought unlikely because the patients showed no signs of fever and no Cuban staff at the embassies fell ill. Simon Denyer, Washington Post, "U.S. Embassy warns citizens in China about mystery sonic illness," 8 June 2018 Without treatment, life-threatening waste and toxins build up in the body with disastrous results. Hilary Decent, Naperville Sun, "Decent: Can anyone spare a kidney?," 25 May 2018 No one knows what actually causes lupus, but viral infections, hormones, genetics and environmental toxins seem to be some of the culprits being studied. NBC News, "What is lupus? What you need to know," 22 Mar. 2018 The same citation included a lack of training on the dangers of mercury, a heavy metal and closely monitored environmental toxin that in high enough concentrations can attack the nervous system of humans and wildlife. John Diedrich, Milwaukee Journal Sentinel, "Workers exposed to hazardous chemicals at St. Francis barrel plant didn't get proper training," 1 Feb. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'toxin.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of toxin

1886, in the meaning defined above

History and Etymology for toxin

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Statistics for toxin

Last Updated

15 May 2019

Look-up Popularity

Time Traveler for toxin

The first known use of toxin was in 1886

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More Definitions for toxin



English Language Learners Definition of toxin

: a poisonous substance and especially one that is produced by a living thing


tox·​in | \ ˈtäk-sən How to pronounce toxin (audio) \

Kids Definition of toxin

: a poison produced by a living thing (as an animal or bacterium)


tox·​in | \ ˈtäk-sən How to pronounce toxin (audio) \

Medical Definition of toxin

: a colloidal proteinaceous poisonous substance that is a specific product of the metabolic activities of a living organism and is usually very unstable, notably toxic when introduced into the tissues, and typically capable of inducing antibody formation

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More from Merriam-Webster on toxin

Rhyming Dictionary: Words that rhyme with toxin

Thesaurus: All synonyms and antonyms for toxin

Spanish Central: Translation of toxin

Nglish: Translation of toxin for Spanish Speakers

Britannica English: Translation of toxin for Arabic Speakers Encyclopedia article about toxin

Comments on toxin

What made you want to look up toxin? Please tell us where you read or heard it (including the quote, if possible).


to speak slightingly about or to degrade

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