toxin

noun tox·in \ ˈtäk-sən \

|Updated on: 10 Jul 2018

Editor's Note: toxins Are Often Found in Nature

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

See toxin defined for English-language learners

See toxin defined for kids

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 of toxin from the Web

Police announced late Wednesday that specialists have determined that a couple in their 40s were poisoned by the same lethal toxin — developed by the Soviet Union — that almost killed Sergei Skripal and his daughter Yulia in March.

— Fox News, "Russian diplomats call Britain 'dumb' to think country would stage nerve agent attack during World Cup: report," 5 July 2018
Tick paralysis is caused by a toxin female ticks release into a host during feeding, reports the American Lyme Disease Foundation.

— cydney henderson, azcentral, "Tick paralysis: 5-year-old suddenly couldn’t walk, had trouble speaking, mom says," 12 June 2018
Surrounded by toxins Juana Leilani recalls the shrill whoops from the chemical alarms that kept sounding as Scud missiles landed around them in Saudi Arabia at the start of the war.

— bill lambrecht, Houston Chronicle, "Veterans Affairs chief’s firing hurt vets’ medical effort," 13 May 2018
Surrounded by toxins Juana Leilani recalls the shrill whoops from the chemical alarms that kept sounding as Scud missiles landed around them in Saudi Arabia at the start of the war.

— bill lambrecht, San Antonio Express-News, "Gulf War Illness," 12 May 2018
Halley said her daughter had been infected by the shiga toxin produce E. coli, often abbreviated as STEC.

— molly sullivan and cathie anderson, sacbee, "Girl, 16, sickened as E. coli outbreak hits Sacramento region | The Sacramento Bee," 25 Apr. 2018
Irregular holes riddle its surface, along with ugly brown spots tinged in yellow—the effects of a toxin produced by the SDS fungus that courses through the plant, robbing it of its pods and chewing up the leaves from the inside out.

— marla broadfoot, Scientific American, "Is This the Next Green Revolution?," 22 Aug. 2017
Long linked to animal deaths, high doses of the toxins in humans can cause liver damage and attack the nervous system.

— Washington Post, "Oregon water scare: Algae blooms happening more often," 22 June 2018
Tick paralysis is thought be caused by a toxin in tick saliva, according to the Centers for Disease and Control.

— ashley may, USA TODAY, "Tick paralysis: 5-year-old suddenly couldn't walk, had trouble speaking, mom says," 12 June 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.

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.

Origin and Etymology of toxin

International Scientific Vocabulary

NEW! Time Traveler

First Known Use: 1886

in the meaning defined above

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toxin Synonyms

TOXIN Defined for English Language Learners

toxin

noun

Definition of toxin for English Language Learners

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

TOXIN Defined for Kids

toxin

noun tox·in \ ˈtäk-sən \

Definition of toxin for Students

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

Medical Dictionary

toxin

noun tox·in \ ˈtäk-sən \

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