poisonous

adjective

poi·​son·​ous ˈpȯiz-nəs How to pronounce poisonous (audio)
ˈpȯi-zᵊn-əs
1
2
a
: 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
3
poisonously adverb

Examples of poisonous in a Sentence

Chocolate is poisonous to dogs. This species of spider is extremely poisonous.
Recent Examples on the Web However, the scientific community long ago debunked the myth that mold was poisonous to breathe. Kelly G. Richardson, San Diego Union-Tribune, 26 Mar. 2024 An Ohio man became seriously ill in 2022 after eating poisonous mushrooms, also misidentified by an app. Tatum Hunter, Washington Post, 18 Mar. 2024 There's conflicting information online about poisonous foods and plants, and taking their advice could land you a trip to the hospital. 7. Kim Komando, USA TODAY, 22 Feb. 2024 For the first time in decades, California is tightening its rules on workplace exposure to lead, a poisonous metal that can wreak havoc throughout the body. Emily Alpert Reyes, Los Angeles Times, 16 Feb. 2024 Then there are the horrific individual acts fueled by poisonous conspiracy rhetoric, such as the 2018 mass shooting at a Pittsburgh synagogue and the recent beheading of a federal employee by his son. Keith Kloor, Scientific American, 9 Feb. 2024 This native plant is poisonous except for the ripe, yellow fruit (discard the seeds, a forager friend says) but people here make May apple jelly and wine. Daryln Brewer Hoffstot Kristian Thacker, New York Times, 23 Mar. 2024 For those planning mushroom hunting, review Michigan’s 50 poisonous mushroom species. Detroit Free Press, 14 Mar. 2024 These poisonous ideas are center stage in the drive to impeach Homeland Security Secretary Alejandro Mayorkas. TIME, 6 Feb. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'poisonous.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

15th century, in the meaning defined at sense 2

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

Dictionary Entries Near poisonous

Cite this Entry

“Poisonous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/poisonous. Accessed 18 Apr. 2024.

Kids Definition

poisonous

adjective
poi·​son·​ous ˈpȯiz-nəs How to pronounce poisonous (audio)
-ᵊn-əs
: containing poison : having or causing an effect of poison
poisonously adverb

Medical Definition

poisonous

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

More from Merriam-Webster on poisonous

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!