poi·​son·​ous | \ ˈpȯiz-nəs How to pronounce poisonous (audio) , ˈpȯi-zᵊn-əs\

Definition of poisonous

2a : having the properties or effects of poison poisonous gas
b : producing a toxic substance that causes injury or death when absorbed or ingested poisonous mushrooms also : venomous a poisonous spider

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Other Words from poisonous

poisonously adverb

Synonyms & Antonyms for poisonous


envenomed, poison, poisoned, toxic, venomous


nonpoisonous, nontoxic, nonvenomous

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Examples of poisonous in a Sentence

Chocolate is poisonous to dogs. This species of spider is extremely poisonous.

Recent Examples on the Web

What took his life; a poisonous snake, an intestinal riot, or desiccation that assaulted and cracked all soft tissue until the organs faulted, one by one? Frank Hutchins, The Courier-Journal, "Bellarmine professor goes face-to-face with the stark realities of the US/Mexican border," 15 July 2019 Five tanker cars carrying anhydrous ammonia ruptured, releasing a cloud of caustic, poisonous gas over the city. Deanna Weniger, Twin Cities, "Local station wants to be source for limited English speaking communities before and after a crisis," 7 July 2019 Historically, Japan’s identity is particularly fraught thanks to a poisonous strain of thought about the uniqueness and superiority of the Japanese race. The Economist, "Ahead of the Tokyo Olympics, Japan ponders what it means to be Japanese," 27 July 2019 In 2017, a 40-year old woman in Yemen's Ibb province is said to have committed suicide by swallowing a poisonous concoction – after first poisoning her two daughters, aged 9 and 12 – according to The New Arab. Fox News, "Family murder suicides in Yemen highlight depths of war-induced mental health crisis," 27 July 2019 In a sign of just how poisonous the association with a private prison can be, big Wall Street banks have also made a rare move: cutting ties with the industry. Lucinda Shen, Fortune, "As Trump Cracks Down on Immigrants, Democrats Go After Private Prisons," 12 July 2019 When pregnant, female snakes seem to deliberately seek out poisonous prey. National Geographic, "Bats regurgitate nectar for their babies—a new discovery," 12 July 2019 Respected and not criticized' The Argentina manager's job, currently held by Lionel Scaloni, is arguably the most poisonous chalice in world football -- the dream job that no Argentine wants to take, but can't turn down. Matias Grez, CNN, "What next for Lionel Messi and Argentina after yet more international failure?," 3 July 2019 Bourgeois said to the best of his knowledge the eels are neither aggressive nor poisonous. Doug Maccash, nola.com, "Asian swamp eels could be coming to a bayou near you," 28 June 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'poisonous.' 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 poisonous

15th century, in the meaning defined at sense 2

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Statistics for poisonous

Last Updated

13 Aug 2019

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Time Traveler for poisonous

The first known use of poisonous was in the 15th century

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English Language Learners Definition of poisonous

: causing sickness or death by entering or touching the body : containing poison
: capable of putting poison into another animal's body by biting it
: very harmful or unpleasant


poi·​son·​ous | \ ˈpȯi-zᵊn-əs How to pronounce poisonous (audio) \

Kids Definition of poisonous

: containing poison : having or causing an effect of poison poisonous mushrooms


poi·​son·​ous | \ ˈpȯiz-nəs, -ᵊn-əs How to pronounce poisonous (audio) \

Medical Definition of poisonous

1 : having the properties or effects of poison poisonous gas
2 : producing a toxic substance that causes injury or death when absorbed or ingested poisonous frogs and plants also : venomous

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Comments on poisonous

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


a haphazard or makeshift solution

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