toxicity

noun

tox·​ic·​i·​ty täk-ˈsi-sə-tē 

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

Brandon died at age 32 of fentanyl and ethanol toxicity on Jan. 29, 2023, after a years-long struggle with an addiction to painkillers. —Francesca Gariano, People.com, 1 Apr. 2025

All this is before most returning residents even begin to test toxicity in their walls and yards and well before the fires widely predicted statewide later this year materialize. —Thomas Elias, Mercury News, 1 Apr. 2025

Meanwhile, acetaminophen toxicity is the leading cause of both acute liver injury and acute liver failure in this country. —Ella Jeffries, Smithsonian Magazine, 28 Mar. 2025

But the supplement is mostly a supportive treatment in children with vitamin deficiencies, and taking too much can cause toxicity. —Ars Technica, 20 Mar. 2025

Word History

First Known Use

1873, in the meaning defined above

Rhymes for toxicity

• basicity
• chronicity
• complicity
• cyclicity
• duplicity
• ethnicity
• facticity
• felicity
• helicity
• plasticity
• publicity
• rusticity

Medical Definition

toxicity

noun

tox·​ic·​i·​ty täk-ˈsis-ət-ē 

plural toxicities

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