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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However, manganese toxicity can develop through inhaling manganese dust, which is associated with some occupations, such as welding and mining. Jillian Kubala, Health, 5 Feb. 2025 This type of graphene has already been used for neural implants without any sign of toxicity, and can even encourage the proliferation of nerve cells. IEEE Spectrum, 3 Feb. 2025 That means the ingredients on their labels might contain more or less of the ingredients promised or other ingredients not listed, which can potentially cause harms such as liver toxicity. Aimee Pugh Bernard, The Conversation, 28 Jan. 2025 Manganese toxicity can also cause lasting neurological damage. Melissa Nieves, Verywell Health, 23 Jan. 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

Dictionary Entries Near toxicity

Cite this Entry

“Toxicity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/toxicity. Accessed 16 Feb. 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

More from Merriam-Webster on toxicity

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