tox·​ic | \ ˈtäk-sik How to pronounce toxic (audio) \

Definition of toxic

 (Entry 1 of 3)

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



Definition of toxic (Entry 2 of 3)

: a toxic substance usually used in plural
variants: or toxico-

Definition of toxic- (Entry 3 of 3)

: poison toxicology

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Synonyms & Antonyms for toxic

Synonyms: Adjective

Synonyms: Noun

Antonyms: Adjective

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Frequently Asked Questions About toxic

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."

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
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Recent Examples on the Web: Adjective The device is completely silent, odor-free, and non-toxic. Travel + Leisure, "The 11 Best Bug-zapping Lamps for Summer," 26 June 2020 These masks are latex free, non-toxic made from non-woven fabric. Yadi Rodriguez, cleveland, "Need a new face mask for coronavirus protection? Here are some of the best on Amazon," 25 June 2020 Thank you for pointing out that almost any smoke residue can be toxic for some people. Amy Dickinson, Detroit Free Press, "Dad needs to rewrite his father’s old scripts," 25 June 2020 The US Food and Drug Administration is warning people not to use certain hand sanitizer products due to the potential presence of methanol, a toxic substance when absorbed through skin or ingested. Elinor Aspegren, USA TODAY, "FDA warns 9 hand sanitizers may contain a potentially fatal ingredient," 23 June 2020 The US Food and Drug Administration is warning people not to use any hand sanitizer from a Mexican manufacturer after finding a potentially fatal toxic substance in some of its products., "Second presidential debate moved from Ann Arbor to Miami," 23 June 2020 The non-toxic, absorbent crystal polymers, which are sewn into the middle chamber, are able to absorb hundreds of times their weight in water, and then this water evaporates during the day to keep you cool. Maggie O'neill,, "7 Cooling Neck Wraps to Help You Regulate Your Body Temperature," 19 June 2020 Despite high levels of chemicals toxic to other animals, the Borax Lake chub thrived in the 10-acre lake, keeping to the edges where temperatures were more suitable. oregonlive, "Rare fish, found only in Oregon, removed from endangered species list," 11 June 2020 Now, a new study reveals that dogs and humans carry the same toxic chemicals in their bodies—a discovery that could possibly improve human health. Carrie Arnold, National Geographic, "Dogs can be 'early-warning systems' for toxic chemical exposure at home," 10 June 2020 Recent Examples on the Web: Noun Their relationship has been fraught and low-key toxic from the beginning, but it's taken time and distance to see that clearly. Ineye Komonibo,, "Hot Insecure Take: Molly And Issa Have Reached The End Of The Road," 15 June 2020 Because the whales feed near shore from the base of the food chain, even sucking up sediments and mud, their scat also could provide information about toxics in the environment, Giles said. Lynda Mapes, Anchorage Daily News, "Migrating gray whales that pause in Puget Sound may hold clues to 2019 die-off," 28 Feb. 2020 Same with non-toxic, because the terms don't have concrete, universal definitions. Lindsay Schallon, Glamour, "13 Healthy, Non-Toxic Nail Polishes That Don’t Chip Immediately," 17 Feb. 2020 More: Would Fab Five revival at Michigan turn Michigan State rivalry toxic? Chris Solari, Detroit Free Press, "Tom Izzo: Michigan State basketball growth spurt just beginning with Michigan next," 3 Jan. 2020 Pollution, from oily toxics to plastics, spills into coastal waters. Craig Welch, National Geographic, "Sea turtles are surviving—despite us," 20 Sep. 2019 Adding certain types of biomass to the soil and covering it in plastic can kill the spores, as the material decomposes and releases gas toxic to bacteria and fungi. Erik Stokstad, Science | AAAS, "Devastating banana disease may have reached Latin America, could drive up global prices," 17 July 2019 From his initial charm to his subsequent gaslighting, Parker's behavior is textbook toxic. Elena Nicolaou,, "Luke Parker Is The New Chad Johnson — But Even Worse," 20 June 2019 Joseph has previously tested its drinking water for 2,4-D, the less toxic of the two chemicals. Rob Davis | The Oregonian/oregonlive,, "Recovery begins on Wallowa Lake barrels that may contain Agent Orange ingredients," 13 June 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'toxic.' 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 toxic


1664, in the meaning defined at sense 1


1890, in the meaning defined above

History and Etymology for toxic


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

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Time Traveler for toxic

Time Traveler

The first known use of toxic was in 1664

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Statistics for toxic

Last Updated

1 Jul 2020

Cite this Entry

“Toxic.” Dictionary, Merriam-Webster, Accessed 10 Jul. 2020.

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More Definitions for toxic


How to pronounce toxic- (audio)

English Language Learners Definition of toxic

: containing poisonous substances


tox·​ic | \ ˈtäk-sik How to pronounce toxic (audio) \

Kids Definition of toxic

: containing, being, or caused by poisonous or dangerous material toxic waste toxic effects


tox·​ic | \ ˈtäk-sik How to pronounce toxic (audio) \

Medical Definition of toxic

 (Entry 1 of 2)

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
3a : affected by a poison or toxin
b : affected with toxemia of pregnancy toxic pregnant women



Medical Definition of toxic (Entry 2 of 2)

: a toxic substance

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tox·​ic | \ ˈtäk-sik How to pronounce toxic (audio) \

Legal Definition of toxic

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

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More from Merriam-Webster on toxic

Thesaurus: All synonyms and antonyms for toxic

Spanish Central: Translation of toxic

Nglish: Translation of toxic for Spanish Speakers

Britannica English: Translation of toxic for Arabic Speakers

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