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 Residents have been complaining loudly about impacts from the fire, most notably citing issues such as noxious odors, vermin, flies and rodents. Tom Bray, Daily News, 14 July 2026 Lineage hired contractors who are measuring this noxious gas and other pollution. Tony Briscoe, Los Angeles Times, 2 July 2026 But the real pleasure is the 303 basslines that squirm in between the drums, coating the soundscapes of the tracks in grime and noxious soot. Andrew Ryce, Pitchfork, 1 July 2026 In other words, France isn’t exactly off the hook for its own noxious pollution. Joe Wilkins, Futurism, 1 July 2026 See All Example Sentences for noxious
Recent Examples of Synonyms for noxious
Adjective
  • Wildfire smoke contains noxious or poisonous gases and particulate matter, tiny particles that can be inhaled deep into the lungs, affecting people with respiratory problems, says the Environmental Protection Agency.
    Janet Loehrke, USA Today, 16 July 2026
  • How plants poisonous to dogs cause harm Not all toxic plants affect dogs the same way, but many share similar chemicals that attack the digestive system.
    Ryan Brennan, Fort Worth Star-Telegram, 15 July 2026
Adjective
  • The as-yet-untitled series will follow the story of multiple families and campaigners including Ellen Roome, who believes that the tragic death of her beloved 14-year-old son Julian ‘Jools’ Sweeney could have been linked to harmful social media.
    Max Goldbart, Deadline, 15 July 2026
  • And planting near any street could expose trees to harmful salt spray when roads are treated in the winter.
    Viveka Neveln, Better Homes & Gardens, 14 July 2026
Adjective
  • Deer-Proof Your Garden To keep your flowers from being gobbled up by deer—one of the most heartbreaking of all garden misfortunes—choose flowers that people find glorious and deer find disgusting.
    Mary Alice Russell, Southern Living, 13 July 2026
  • Where critics see disgusting piles of stuff, hoarders see more.
    Shivali H. Patra, Mercury News, 8 July 2026
Adjective
  • In addition to administering the toxic combination of medications, Hemphill failed to recognize and treat signs of respiratory distress, and administered the incorrect reversal medication for the kind of drug the girl had been given, Spragins wrote.
    Lillie Davidson, Fort Worth Star-Telegram, 16 July 2026
  • How many malodorously toxic episodes does that make toward the seven plagues in the Old Testament?
    Patt Morrison, Los Angeles Times, 15 July 2026
Adjective
  • Teri handled higher-value finds and saw that potentially dangerous items – like firearms and knives – got to the local sheriff’s office.
    Alisha Ebrahimji, CNN Money, 6 July 2026
  • Looking back through the sequence, Brazil have good numbers back and there is little need for anyone to overcommit — but a lazy tackle from behind leads to a free kick in a dangerous area.
    Mark Carey, New York Times, 6 July 2026
Adjective
  • The deals defined one of the ugliest chapters of Russia’s transition to capitalism in the 1990s.
    Simon Shuster, The Atlantic, 17 July 2026
  • Leaders must be grounded in self-awareness and their influence, leaning into emotional intelligence and humility; recognizing that different styles shape how people show up amid many influences, good, bad and ugly.
    Expert Panel®, Forbes.com, 17 July 2026
Adjective
  • From downtown Los Angeles to the San Gabriel Valley, tens of thousands were enveloped in unhealthful levels of smoke, even as some local officials told residents that the air posed no danger.
    Tony Briscoe, Los Angeles Times, 2 July 2026
  • The soil may contain pathogens, pesticides and other unhealthful things.
    Joan Morris, Mercury News, 9 Feb. 2026
Adjective
  • These conditions can increase your vulnerability to adverse effects from poor air quality.
    Southern California Weather Report, Oc Register, 4 July 2026
  • Valentine also testified that the FDA encourages infant formula companies to send in all adverse event reports and that nothing prevented Mead Johnson from doing so.
    David Hilzenrath, USA Today, 2 July 2026

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Cite this Entry

“Noxious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/noxious. Accessed 20 Jul. 2026.

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