toxicity

noun

tox·​ic·​i·​ty täk-ˈsi-sə-tē How to pronounce toxicity (audio)
plural toxicities
: the quality or state of being toxic: such as
a
: the quality, state, or relative degree of being poisonous
measuring the toxicity level of the soil
The toxicity of some chemical agents degrades significantly over time, so it is unclear how lethal the stockpiles are.David S. Cloud
Administering a cocktail of drugs would dilute the toxicities of the different drugs and minimize the development of viral resistance to them.Rudy M. Baum and Ron Dagani
b
: an extremely harsh, malicious, or harmful quality
In the past few days, I've tuned in to C-SPAN to watch a number of the televised Senate debates, which illustrate all too vividly the toxicity of an uncivil tongue.Connie Schultz
In much of the ensuing commentary, court watchers worried that the justices' soaring rates of written dissents, nasty and personal attacks and scathing remarks read aloud from the bench bespeak a new toxicity in Supreme Court discourse.Dahlia Lithwick

Did you know?

Toxicity is often a relative thing; in the words of a famous old saying, "The dose makes the poison". Thus, it's possible to die from drinking too much water, and lives have been saved by tiny doses of arsenic. Even though botulinum toxin is the most toxic substance known, it's the basic ingredient in Botox, which is injected into the face to get rid of wrinkles. With some poisons, mere skin contact can be lethal; others are lethal when breathed into the lungs in microscopic amounts. To determine if a chemical will be officially called a poison, researchers often use the "LD50" test: If 50 milligrams of the substance for every kilogram of an animal's body weight results in the death of 50% of test animals, the chemical is a poison. But there are problems with such tests, and toxicity remains a very individual concept.

Examples of toxicity in a Sentence

Recent Examples on the Web
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If there is a pervasive sense of contempt for management or a disregard for the work product, that is a clear sign of toxicity. Rolling Stone Culture Council, Rolling Stone, 10 Sep. 2025 The show offers a fantasy of a culture not so plagued by toxicity, allowing the creators to exchange the politics of the day for the nuances of growing up. Greta Rainbow, The Atlantic, 10 Sep. 2025 Saeed also argues that organic produce can be just as heavily sprayed as other produce and that organic pesticides may have a high level of toxicity. Joshua Siskin, Oc Register, 10 Sep. 2025 Both pastors said the Bible and their churches provide safeguards to curb the toxicity found in some parts of the manosphere. Marc Ramirez, USA Today, 9 Sep. 2025 See All Example Sentences for toxicity

Word History

First Known Use

1873, in the meaning defined above

Time Traveler
The first known use of toxicity was in 1873

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Cite this Entry

“Toxicity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/toxicity. Accessed 17 Sep. 2025.

Medical Definition

toxicity

noun
tox·​ic·​i·​ty täk-ˈsis-ət-ē How to pronounce toxicity (audio)
plural toxicities
: the quality, state, or relative degree of being toxic or poisonous

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