tox·​ic·​i·​ty | \ täk-ˈsi-sə-tē How to pronounce toxicity (audio) \
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 These longer-term experiments will also give the researchers the opportunity to do more testing for toxicity and other side effects. Katherine J. Wu, Smithsonian, "This Spiky Patch Could Invisibly Record Vaccination History Under Skin," 18 Dec. 2019 The toxicology results for Hill, sent via the Cape & Islands District Attorney's Office, revealed methadone and ethanol toxicity as well as other prescription medications were found in Hill's system at the time of her Aug. 1 death. Leora Arnowitz, USA TODAY, "Robert F. Kennedy's granddaughter, Saoirse Kennedy Hill, died of accidental overdose," 1 Nov. 2019 The company must prove that the drug has a relatively low potential for toxicity and abuse. Sarah Lynch, The Conversation, "How birth control pill prescriptions by a pharmacist could broaden access and keep costs down," 7 Oct. 2019 To Pinterest, for taking a stand against social media toxicity. Kevin Roose, New York Times, "The 2019 Good Tech Awards," 30 Dec. 2019 Managing the waste will require new technologies to reduce its volume and toxicity. Washington Post, "Japan revises Fukushima cleanup plan, delays key steps," 27 Dec. 2019 In a statement, Sarepta said the FDA denied the approval because of the risk of infections related to intravenous infusion ports and kidney toxicity seen in animal experiments., "Under its gene therapy licensing deal with Roche, Sarepta is eligible to receive up to $1.7 billion, in addition to the $1.1 billion, if the experimental treatment meets certain regulatory and sales goals, plus royalties on sales.," 24 Dec. 2019 Reports of pesticides and heavy metals in CBD have also raised questions about its safety and toxicity, Abernethy said. Scottie Andrew, CNN, "FDA warns 15 companies for illegally selling CBD products," 26 Nov. 2019 Matthew Davis, a spokesman for Solano County, said officials there found no rise in levels of toxicity and particulate matter due to the smoke rising into the upper atmosphere. Matthias Gafni,, "NuStar fire: Smoke was a problem after Crockett explosions, but lack of wind kept toxins away," 21 Oct. 2019

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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The first known use of toxicity was in 1879

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Statistics for toxicity

Last Updated

18 Jan 2020

Cite this Entry

“Toxicity.” The Dictionary, Merriam-Webster Inc., Accessed 26 January 2020.

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More Definitions for toxicity


How to pronounce toxicity (audio)

English Language Learners Definition of toxicity

technical : the state of being poisonous or the degree to which something (such as a drug) is poisonous


tox·​ic·​i·​ty | \ täk-ˈsis-ət-ē How to pronounce toxicity (audio) \
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

Comments on toxicity

What made you want to look up toxicity? Please tell us where you read or heard it (including the quote, if possible).


to express in a more acceptable way

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