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

His two presidential campaigns planted seeds that would bear poisonous fruit 20 years later. Steve Chapman, chicagotribune.com, "Column: Ross Perot paved the way for Donald Trump," 9 July 2019 The pair's angry high-schooler son, Connor (Judah Lewis), is resolutely siding with his father in this domestic turf war, creating a poisonous mood at home. Stephen Dalton, The Hollywood Reporter, "'I See You': Film Review | Edinburgh 2019," 8 July 2019 In its efforts to stop opioid sales on the site, Facebook appears to be blocking people who warn users about poisonous batches of drugs or who supply materials used to test for fentanyls and other contaminants. Casey Newton, The Verge, "A conservative audit of Facebook’s speech policies is running behind schedule," 3 July 2019 Dead zones in the oceans today emit poisonous hydrogen sulfide. Letter Writers, Twin Cities, "Letters: Too many trucks where trucks don’t belong," 29 June 2019 Six men were sent to a farm in Coimbatore to clean the septic, out of which three died due to inhalation of poisonous gas, suggest media reports. Niharika Sharma, Quartz India, "India’s most demeaning job killed over 100 people in two years, but is anyone bothered?," 28 June 2019 The winter settled in like a poisonous fog around the redundant American people. Nell Zink, Harper's magazine, "Marmalade Sky," 24 June 2019 The tunnels connected the residents with subterranean schools and hospitals, and included booby traps smeared with poisonous concoctions to injure enemy soldiers. National Geographic, "Southeast Asia Family Journey: Vietnam to Cambodia," 12 June 2019 Restrictive clothing, poisonous products, fake health trends, and unsafe working conditions have a long history of fashion victims. Serah-marie Mcmahon, Teen Vogue, "This New Book Is All About the Dark (And Sometimes Bloody) History of Fashion," 12 Apr. 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

16 Jul 2019

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Time Traveler for poisonous

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

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More Definitions for poisonous



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).


characterized by aphorism

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