Definition of noxiousnext
1
as in poisonous
bad for the well-being of the body mixing bleach and ammonia can cause noxious fumes that can seriously harm you

Synonyms & Similar Words

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Antonyms & Near Antonyms

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Synonym Chooser

How is the word noxious different from other adjectives like it?

Some common synonyms of noxious are baneful, deleterious, detrimental, and pernicious. While all these words mean "exceedingly harmful," noxious applies to what is both offensive and injurious to the health of a body or mind.

noxious chemical fumes

When is it sensible to use baneful instead of noxious?

The words baneful and noxious can be used in similar contexts, but baneful implies injury through poisoning or destroying.

the baneful notion that discipline destroys creativity

When would deleterious be a good substitute for noxious?

In some situations, the words deleterious and noxious are roughly equivalent. However, deleterious applies to what has an often unsuspected harmful effect.

a diet found to have deleterious effects

When could detrimental be used to replace noxious?

While the synonyms detrimental and noxious are close in meaning, detrimental implies obvious harmfulness to something specified.

the detrimental effects of excessive drinking

When might pernicious be a better fit than noxious?

The meanings of pernicious and noxious largely overlap; however, pernicious implies irreparable harm done through evil or insidious corrupting or undermining.

the claim that pornography has a pernicious effect on society

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of noxious Classic examples include blocking a public road, polluting a waterway or emitting noxious fumes. Diana Novak Jones, USA Today, 4 May 2026 After years of trying to acquire Infowars—the far right media company founded by Sandy Hook conspiracy theorist Alex Jones—Collins and his satirical paper were finally set to receive court approval to move forward with their takeover of the internet’s most noxious URL. Chris Murphy, Vanity Fair, 30 Apr. 2026 Director Allen paces the reveals and developments – whether noxious or as sweet as the first blush of love in little Zonia and neighbor boy Reuben (Jackson Edward Davis at the review performance) – with an artful sense of the narrative’s timings and rhythms. Greg Evans, Deadline, 25 Apr. 2026 The practice has had horrible consequences for the Black, working class neighborhood where the turbines are located, whose residents are stuck breathing xAI’s noxious exhaust. Joe Wilkins, Futurism, 16 Apr. 2026 See All Example Sentences for noxious
Recent Examples of Synonyms for noxious
Adjective
  • Foxglove Foxglove features beautiful trumpet-like blossoms that are poisonous to cats.
    Amy DeYoung, USA Today, 3 June 2026
  • Some have thorns or spines, others have poisonous leaves or berries, and still others have…elaborate chemical defense alarm systems?
    Regina G. Barber, NPR, 3 June 2026
Adjective
  • Platforms will be required to introduce safety-by-design features, including protections against manipulative design that encourages compulsive use, and take action against underage accounts and harmful content.
    ABC News, ABC News, 1 June 2026
  • In addition to being harmful to humans, certain types of mushrooms can be poisonous to pets if consumed.
    Sacbee.com, Sacbee.com, 1 June 2026
Adjective
  • The president announced the work in April during an unrelated Oval Office appearance, saying he was inspired by complaints from a friend visiting from Germany who called the pool dark and disgusting.
    Los Angeles Times, Los Angeles Times, 4 June 2026
  • Seeing a game get shipped off to a foreign land for no good reason is even more disgusting.
    Austin Perry OutKick, FOXNews.com, 3 June 2026
Adjective
  • All parts of the plant are toxic if eaten.
    Tim Johnson, Chicago Tribune, 6 June 2026
  • Prosecutors argued at trial that Shirilla drove into the building to end her toxic relationship with Russo, and that Flanagan was an unintended victim who happened to be in the car.
    Sarah Rumpf-Whitten, FOXNews.com, 6 June 2026
Adjective
  • Brith had shut her eyes, finding that the sparks were still living on the inside of the lids, vivid in their dangerous dark.
    Maggie O’Farrell, Literary Hub, 2 June 2026
  • Carpenter says the disturbing encounters left her fearful for her safety and that of relatives living with her, as police label the suspect’s fixation irrational and increasingly dangerous.
    Emily St. Martin, Los Angeles Times, 2 June 2026
Adjective
  • Lemieux was 37, and had a reputation as one of those players who knew where to be, and when, around the ugly areas on the ice in a playoff game.
    Mac Engel May 29, Fort Worth Star-Telegram, 29 May 2026
  • We, viewers and voters, are subjected to very ugly photographs and rhetoric.
    DP Opinion, Denver Post, 29 May 2026
Adjective
  • Onshore winds are pushing smoke from the Sandy fire into Los Angeles County, where neighborhoods from the San Fernando Valley to Arcadia could face unhealthful air for sensitive groups.
    Los Angeles Times, Los Angeles Times, 22 May 2026
  • The soil may contain pathogens, pesticides and other unhealthful things.
    Joan Morris, Mercury News, 9 Feb. 2026
Adjective
  • DeVries also feels that seniors should not hesitate to file police reports to document adverse incidents.
    Karie Angell Luc, Chicago Tribune, 5 June 2026
  • The drug is designed to rapidly block platelets from clumping and restricting blood flow, lessening the adverse outcomes of a heart attack.
    Justin Zacks, CNBC, 4 June 2026

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Cite this Entry

“Noxious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/noxious. Accessed 7 Jun. 2026.

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