toxic
Americanadjective
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of, pertaining to, affected with, or caused by a toxin or poison.
a toxic condition.
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acting as or having the effect of a poison; poisonous.
a toxic drug.
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causing unpleasant feelings; harmful or malicious: toxic criticism.
a toxic boyfriend who wanted complete control over her;
toxic criticism.
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Finance.
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pertaining to or noting debt that will probably not be repaid.
toxic mortgages.
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pertaining to or noting a financial instrument or other asset that has no value or an unknown value because there is no market for it.
toxic mortgage-backed securities.
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noun
adjective
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of, relating to, or caused by a toxin or poison; poisonous
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harmful or deadly
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(of a financial asset) likely to cause significant loss to the holder
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Relating to or caused by a toxin.
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Capable of causing injury or death, especially by chemical means; poisonous.
Other Word Forms
Etymology
Origin of toxic
First recorded in 1655–65; from Late Latin toxicus “poisonous,” derivative of toxicum “poison,” from Greek toxikón (for toxikòn phármakon literally, “bow poison,” i.e., poison used on arrows), equivalent to tóx(on) “bow” + -ikon, neuter of -ikos adjective suffix; see -ic
Explanation
Danger! Hazardous! Do not eat! These are just some of the warnings you'll see on toxic substances — meaning stuff that's poisonous and even deadly. Cobra bites, wild mystery mushrooms and strong chemicals are all toxic. So are certain people, if they have particularly mean personalities. Toxic is related to the word toxin, which is a kind of poison. It comes from the ancient Greek word toxikon, which means "poison for arrows." Some toxic arrows could come in handy for those toxic personalities...
Vocabulary lists containing toxic
Holes
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"Handle with Care"
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The Cardboard Kingdom
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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.
The financial system looks vulnerable to a toxic mix of higher interest rates and a slowing economy.
From MarketWatch • May 20, 2026
These microscopic particles act as drugs themselves, helping the brain restore its own natural cleaning system and dramatically reducing toxic protein buildup linked to Alzheimer's disease.
From Science Daily • May 17, 2026
Two toxic air contaminants present in California’s ambient air, acrolein and ethylene oxide, appear to be much stronger carcinogens than previously known, California environmental health officials announced Thursday.
From Los Angeles Times • May 14, 2026
Mountbatten-Windsor has been toxic for the reputation of royals and their finances.
From BBC • May 14, 2026
I was never very polite after one of those episodes, and that day—my birthday—I felt particularly toxic for the humiliation of having been given a bath by my stepmother.
From "100 Sideways Miles" by Andrew Smith
Definitions 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.
