poisonous
Americanadjective
-
full of or containing poison.
poisonous air; a poisonous substance.
-
harmful; destructive.
poisonous to animals; poisonous rumors.
-
deeply malicious; malevolent.
poisonous efforts.
adjective
-
having the effects or qualities of a poison
-
capable of killing or inflicting injury; venomous
-
corruptive or malicious
Other Word Forms
Etymology
Origin of poisonous
Compare meaning
How does poisonous compare to similar and commonly confused words? Explore the most common comparisons:
Explanation
What do arsenic, cyanide, and bleach all have in common? They're poisonous. In other words, if you ingest these poisonous chemicals, you will most likely die or become very ill. If something is poisonous, you'd better not eat, drink, inhale, or touch it: it will make you sick. Some poisonous materials can even kill you. Of course, this adjective is derived from the noun poison, which is a toxic substance. You can also calls things poisonous if they're harmful in less physical ways. Spreading lies about someone is poisonous. Betraying a friend is poisonous. What both kinds of poisonous things have in common is that they do damage.
Vocabulary lists containing poisonous
Week 4 Vocabulary
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Harmful, List 2
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
-ious, -eous, -ous
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Indonesia's government says tens of thousands of personnel are fighting the fires, but the air in Palangkaraya remains poisonous, with the haze turning the sky apocalyptic orange in the late afternoon.
From Barron's ● Oct. 15, 2026
He announced that the UK would set up a new centre to "stem the poisonous tide" of disinformation.
From BBC ● Oct. 11, 2026
The azure shimmer of the blue morpho confuses predators, while monarchs’ vibrant orange-and-black wings warn birds and other predators that they are poisonous.
From The Wall Street Journal ● Aug. 3, 2026
The Pluskal Group, including Mutabdžija, was studying the same difficult family of diterpenoid alkaloids in wolfsbane, a famously poisonous relative of larkspur that is also known as monkshood.
From Science Daily ● Aug. 3, 2026
The black smoke hadn't found its way down to the lower floors yet, but the air tasted gritty and poisonous.
From "A Wish in the Dark" by Christina Soontornvat
Random Word
Spin the wheel and learn a new word!
Get a wordDefinitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
