toxic

1 of 3

adjective

tox·​ic ˈtäk-sik 

1

: containing or being poisonous material especially when capable of causing death or serious debilitation

toxic waste

a toxic radioactive gas

an insecticide highly toxic to birds

2

: exhibiting symptoms of infection or toxicosis

the patient became toxic two days later

3

: extremely harsh, malicious, or harmful

toxic sarcasm

4

: relating to or being an asset that has lost so much value that it cannot be sold on the market

toxic

2 of 3

noun

: a toxic substance

—usually used in plural

toxic-

3 of 3

combining form

variants or toxico-

: poison

toxicology

Synonyms

Adjective

• envenomed
• poison
• poisoned
• poisonous
• venomous

Noun

• bane
• poison
• toxin
• venom

Examples of toxic in a Sentence

Adjective

The fumes from that chemical are highly toxic.

Tests will be run to determine if the landfill is toxic.

Noun

tested for toxics in the water supply

Recent Examples on the Web

Adjective

Russia has consistently denied using chemical weapons in Ukraine and, in turn, has accused Kyiv of employing toxic agents on the battlefield. —Michael D. Carroll, Newsweek, 18 Dec. 2024

Most of the concern comes from lab studies involving animals or human cell lines — scientists observed toxic effects of microplastics on the cellular and molecular levels. —Will Stone, NPR, 18 Dec. 2024

Noun

Fipronil is also high toxic to fish and aquatic invertebrates. —Scott Travers, Forbes, 22 Nov. 2024

According to Apolo, theobromine, an alkaloid in the cacao beans used to make chocolate, makes chocolate toxic to canines. —Kelli Bender, People.com, 29 Oct. 2024

Word History

Etymology

Adjective

Late Latin toxicus, from Latin toxicum poison, from Greek toxikon arrow poison, from neuter of toxikos of a bow, from toxon bow, arrow

Combining form

New Latin, from Latin toxicum

First Known Use

Adjective

1664, in the meaning defined at sense 1

Noun

1687, in the meaning defined above

Phrases Containing toxic

• toxic shock
• toxic shock syndrome
• toxic waste
• toxic (waste) dump

Kids Definition

toxic

adjective

tox·​ic

ˈtäk-sik

1

: of, relating to, or caused by a poison or toxin

2

: poisonous

toxicity

täk-ˈsis-ət-ē

noun

Etymology

Adjective

from Latin toxicus "relating to or caused by a poison," from earlier toxicum "poison," from Greek toxikon "a poison put on the tips of arrows," from toxikos "of a bow and arrows," from toxon "bow, arrow" — related to intoxicate, toxin see Word History at intoxicate

Medical Definition

toxic

1 of 2 adjective

tox·​ic ˈtäk-sik 

1

: containing or being poisonous material especially when capable of causing serious injury or death

toxic drugs

toxic gas

2

: of, relating to, or caused by a poison or toxin

toxic liver damage

3

a

: affected by a poison or toxin

b

: affected with toxemia of pregnancy

toxic pregnant women

toxic

2 of 2 noun

: a toxic substance

Legal Definition

toxic

adjective

tox·​ic ˈtäk-sik 

1

: containing or being poisonous material especially when capable of causing death or serious debilitation

2

: having substantially lowered worth

specifically : relating to or being an asset that has lost so much value that it cannot be sold on the market

toxic assets

toxic subprime loans