toxic

noun

: a toxic substance

—usually used in plural

Frequently Asked Questions

What is the difference between toxic and poisonous?

The words toxic and poisonous are in many ways synonymous and interchangeable. Each word appears in at least one of the other’s definitions; one of the definitions of poisonous is "producing a toxic substance that causes injury or death when absorbed or ingested," and one of the definitions of toxic is "containing or being poisonous material especially when capable of causing death or serious debilitation." There are some ways in which they differ, such as when toxic refers to an actual toxin which is the product of a living organism while poisonous refers to a poison which may be artificially created.

What is the difference between toxic and noxious?

Toxic and noxious mean very similar things, but toxic has a connotation of severe harm or lethality more than noxious does. Both words have broadened figurative meanings as well.

What is a toxic person?

In addition to its original meaning concerning debilitating or lethal poisons, toxic has some figurative senses. Toxic can mean "extremely harsh, malicious, or harmful," which is often the intention when describing an individual as "toxic."

Synonyms of toxic

• poison
• disease
• toxin

Examples of toxic in a Sentence

tested for toxics in the water supply

Recent Examples on the Web

At the same time, the Trump administration has taken steps to roll back regulations on emissions from industrial facilities, such as mercury and other toxics emitted from coal plants. —Los Angeles Times, 27 May 2026

Portside residents face higher cancer risk from air toxics than 93% of the nation. —Jose Franco Garcia, San Diego Union-Tribune, 12 May 2026

Asparagus releases a chemical toxic to root knot nematodes, a microscopic round worm that creates multiple disease and growth problems in tomatoes, eggplant, potatoes and peppers. —Barbara Gillette, The Spruce, 3 May 2026

Manufacturers should be diligently working to clean up their supply chains and manufacturing practices to ensure their products are free of PFAS and other toxics. —Sarah Todd, STAT, 1 May 2026

Word History

First Known Use

1687, in the meaning defined above

Phrases Containing toxic

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

Rhymes for toxic

• anoxic
• hypoxic
• nontoxic
• antitoxic
• cytotoxic
• genotoxic
• nephrotoxic
• neurotoxic
• phytotoxic
• hepatotoxic

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

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