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 Officers punched him, covered his face, poured a noxious liquid over him and threatened him with further abuse. — Antonio María Delgado, Miami Herald, 8 Oct. 2026 Just a noxious river of sludge and foul wind enveloping everything in the vicinity. — Josh Brown,sean Russo, CNBC, 8 Oct. 2026 Delphi sits above a geologic vent, an X from which noxious gases escaped the earth, corrupting the minds of women who inhaled and pronounced their prophecies. — Literary Hub, 6 Oct. 2026 Functional connectivity in the fetal brain develops substantially later in gestation, with measurable differences in brain activity and facial responses to noxious versus innocuous stimulation appearing at approximately 33 weeks. — Arkansas Online, 3 Oct. 2026 See All Example Sentences for noxious
Recent Examples of Synonyms for noxious
Adjective
  • But major questions remained about how much space exists inside the Earth to store the CO2, how effectively it could be monitored and whether the poisonous, concentrated gas would reliably stay underground.
    — Katie Worth, ProPublica, 30 Oct. 2026
  • Mirroring the poisonous arena featured in the movie, Grace paired her vibrant, beaded Almée Couture gown with a high ponytail, leaving her blond bangs out to frame her face.
    — Arushi Jacob, Footwear News, 29 Oct. 2026
Adjective
  • If our minds are constantly running at full throttle, potentially harmful molecules might keep piling up faster than the brain can dispose of them.
    — Cody Cottier, Scientific American, 4 Nov. 2026
  • Earth's ozone layer acts as a planetary sunscreen, shielding humans, animals, and plants from harmful ultraviolet (UV) radiation.
    — Dan Peck, ABC News, 4 Nov. 2026
Adjective
  • Not only has the gimmick run stale, but her insistence on upping the ante year after year, creating costumes that are increasingly bizarre and disgusting, is a threat to us all.
    — Tom Smyth, Vulture, 29 Oct. 2026
  • The actions of their fans, especially their supporter group, was disgusting.
    — Jon Root OutKick, FOXNews.com, 24 Oct. 2026
Adjective
  • Gill and Krukoff separately pushed their way into Indigenous communities, bribing or cajoling elders to forage vines and process toxic plant compounds known as curare.
    — The New Yorker, New Yorker, 2 Nov. 2026
  • Concern over plastic in the kitchen and its affects on the endocrine system has been growing for the past few years, Nathan said, referencing a viral article that linked black plastics in the kitchen to alarming levels of toxic flame retardants.
    — Jordan Valinsky, CNN Money, 2 Nov. 2026
Adjective
  • People talking to an AI in an abusive and cruel way are more likely to be associated with trying to get the AI model to engage in dangerous requests, like trying to get around an AI’s safety guardrails, Campbell added.
    — Hadas Gold, CNN Money, 1 Nov. 2026
  • Hazing involves requiring new or potential recruits to the military or college fraternities to perform strenuous, humiliating or dangerous tasks.
    — Natasha Holt, FOXNews.com, 1 Nov. 2026
Adjective
  • The warehouse retailer stock was one of just three Club names in the green in Thursday's ugly market.
    — Natasha Abellard, CNBC, 5 Nov. 2026
  • And not least because no amount of overuse can obscure the ugly origin of 2026’s favorite syntaxx.
    — Hillary Busis, Vanity Fair, 5 Nov. 2026
Adjective
  • Warnings of unhealthful air quality remained in effect Saturday across a wide swath of the United States due to smoke from Canadian wildfires that has engulfed the Northeast in haze for days.
    — Los Angeles Times, Los Angeles Times, 18 July 2026
  • The soil may contain pathogens, pesticides and other unhealthful things.
    — Joan Morris, Mercury News, 9 Feb. 2026
Adjective
  • Floodplain alterations cannot have adverse upstream or downstream effects, and earthen flood barriers, or any other interruption to the natural flow of flood water, is prohibited.
    — Matthew Adams, Fort Worth Star-Telegram, 30 Oct. 2026
  • Studies have found oil wells can emit carcinogens and are linked to adverse health effects including respiratory issues, headaches, throat irritation and other problems.
    — Los Angeles Times, Los Angeles Times, 28 Oct. 2026

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Cite this Entry

“Noxious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/noxious. Accessed 6 Nov. 2026.

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