tox·ic·i·ty | \täk-ˈsi-sə-tē \
plural toxicities

Definition of toxicity 

: 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

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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

It is considered highly toxic to fish and bees, but low in toxicity to birds, according to the center. Scott Dance,, "Dealing with more bug bites than usual? Mosquitos are at 3 times their normal number in Maryland this summer.," 5 July 2018 As for streaming services, Hulu Tuesday yanked its Roseanne reruns, indicating a level of toxicity likely to deter others. Andrea Mandell, USA TODAY, "What happens to 'Roseanne'? Racist tweet likely Barrs revival elsewhere, even without her," 30 May 2018 The next steps are to scale that production up to hundreds of grams or pounds, Sabatini says, so that full toxicity screenings can be done as well as explosive tests in the field. Jay Bennett, Popular Mechanics, "So Long TNT, There's a New Explosive in Town," 2 July 2018 One factor will be toxicity: Glass breaks, and many solar window technologies contain a small amount of toxic materials. Robert F. Service, Science | AAAS, "Skyscrapers could soon generate their own power, thanks to see-through solar cells," 28 June 2018 The most common causes are toxicity from certain medications and infection with hepatitis viruses, according to the Merck Manual. Naseem S. Miller,, "Florida Hospital performs first pediatric liver transplant in Orlando," 23 May 2018 If anything, Breath, which makes excellent use of Paris’ low-rise topography, could be read as a warning sign against the dangers of pollution for a city that has seen an alarming increase in toxicity rates over the past years. Jordan Mintzer, The Hollywood Reporter, "'Just a Breath Away' ('Dans la brume'): Film Review," 9 Apr. 2018 Mashup self-portraits by Tim Hawkinson have likewise been exhibited before at the gallery and in this context take on a new toxicity: historical, literary and biological. Charles Desmarais,, "Summer exhibition at Hosfelt Gallery a monstrous affair," 6 July 2018 The toxicity of the environment shreds the quality of conversation and deters meaningful participation in it. Franklin Foer, The Atlantic, "The Death of the Public Square," 6 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'toxicity.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of toxicity

1879, in the meaning defined above

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Statistics for toxicity

Last Updated

11 Oct 2018

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Time Traveler for toxicity

The first known use of toxicity was in 1879

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More Definitions for toxicity


tox·ic·i·ty | \täk-ˈsis-ət-ē \
plural toxicities

Medical Definition of toxicity 

: the quality, state, or relative degree of being toxic or poisonous

More from Merriam-Webster on toxicity

Spanish Central: Translation of toxicity

Nglish: Translation of toxicity for Spanish Speakers

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