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



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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 Perfectly edible plants can look nearly identical to perfectly poisonous ones. Hannah Goldfield, The New Yorker, "Foraged Foods Shorten the Supply Chain," 26 June 2020 As chemical plant production increased, there were deadly explosions, train derailments of rail cars containing deadly poisonous gases, fires, leaks requiring citizens to shelter in their homes and ever-present acrid odors. James Bruggers, The Courier-Journal, "Louisville’s 'Black Lives Matter' protests echo a long quest for environmental justice," 18 June 2020 Dozens of tons of lead went up in flames during the fire, sending tons of poisonous lead dust onto the surrounding ground. USA TODAY, "Restoration work to begin 1 year after Notre Dame cathedral fire," 8 June 2020 Show us your intolerance for poisonous voices, particularly among those responsible for promotion, retention and innovation. Roy S. Johnson | Rjohnson@al.com, al, "Johnson: 2020 meet 1968 -- This time we must do better. Here’s how," 15 June 2020 While a steady diet of cinnamon applesauce is not recommended, cinnamon is not poisonous to dogs. Heloise, Washington Post, "Hints From Heloise: Is cinnamon okay for Fido?," 13 June 2020 Those interested in skyflower should beware that the berry is poisonous to humans, so the plant might not be the best choice for a household with small children. Kimi Robinson, azcentral, "Refresh your patio or balcony on a budget with 7 DIY ideas that are perfect for Phoenix," 12 June 2020 The cane toad, also known as the bufo toad, is a poisonous amphibian that, when provoked, is known to produce a milky white toxin on its back, a substance that can be particularly dangerous to house pets. Jay Cannon, USA TODAY, "Florida tells residents to humanely kill these invasive, toxic toads that are lethal to pets," 12 June 2020 In 2012, North Korean agents attempted to assassinate him with a poisonous needle shaped like a pen. Joshua Berlinger, CNN, "North Korea isn't talking to the South anymore. Experts say it could be trying to manufacture a crisis," 9 June 2020

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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Time Traveler for poisonous

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

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Statistics for poisonous

Last Updated

1 Jul 2020

Cite this Entry

“Poisonous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/poisonous. Accessed 8 Jul. 2020.

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More Definitions for poisonous


How to pronounce poisonous (audio)

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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