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

Tests have shown that the sperm-nanoparticle clusters remain biocompatible, causing no significant toxicity to human uterine cells even after 72 hours of exposure. —Neetika Walter, Interesting Engineering, 5 Sep. 2025

In late March, Covenant Children’s Hospital, in nearby Lubbock, reported treating a small number of unvaccinated children with measles who were also suffering from vitamin-A toxicity. —Tom Bartlett, The Atlantic, 3 Sep. 2025

The opposite leads to toxicity. —Alora Bopray, USA Today, 3 Sep. 2025

This is why general-purpose models that address surface-level toxicity or misinformation won’t cut it in this environment. —David Talby, Forbes.com, 2 Sep. 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