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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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 Dry fields are also vulnerable to noxious weeds like leafy spurge and toadflax, which are toxic to cattle and unpalatable to native ungulates like deer and pronghorn antelope. Krista Kafer, Denver Post, 7 Apr. 2026 Bully feels custom-designed to please the diehards exhausted by his noxious antics. Kieran Press-Reynolds, Pitchfork, 1 Apr. 2026 Over time, however, the culture on the ground became just as noxious as Ye’s most unhinged instincts. Jeff Ihaza, Rolling Stone, 31 Mar. 2026 Helpful sources at your university agricultural extension program can usually confirm the identity of noxious weeds like giant hogweed and poison hemlock. Natalie Krebs, Outdoor Life, 26 Mar. 2026 See All Example Sentences for noxious
Recent Examples of Synonyms for noxious
Adjective
  • Hydrangeas are poisonous to dogs and cats.
    Sophia Beams, Better Homes & Gardens, 2 May 2026
  • Restoring the balance of the humors through profusely bleeding the patient or inducing vomiting or diarrhea with the poisonous plant hellebore.
    Literary Hub, Literary Hub, 28 Apr. 2026
Adjective
  • The physical displacement drives the flow of CSF through the brain’s tissues, potentially carrying away harmful waste products.
    Khloe Quill, FOXNews.com, 11 May 2026
  • None of this makes AI harmful in itself.
    Jonathan Avery, STAT, 11 May 2026
Adjective
  • This administration has unleashed a disgusting anti-immigrant agenda.
    Lucas Robinson, San Diego Union-Tribune, 7 May 2026
  • Let women be monstrous, disgusting, angry, feral creatures!
    Literary Hub, Literary Hub, 4 May 2026
Adjective
  • Northern India already has some of the world’s most polluted air, created by a toxic mix of vehicle and industrial emissions, crop residue burning, and construction dust.
    Ayushi Shah, CNN Money, 9 May 2026
  • Veterinarians recommend knowing which flowers are toxic, which are safer for pets and what to do if exposure happens.
    Taneia Surles, USA Today, 9 May 2026
Adjective
  • Battista and Tucker are two of the most dangerous hitters in the state.
    Paul Johnson, Chicago Tribune, 12 May 2026
  • If Iran gets away with charging any kind of toll or fee for passing through it, that principle is shot, and that is a dangerous thing.
    Eliot A. Cohen, The Atlantic, 11 May 2026
Adjective
  • The scene Tuesday was beyond ugly.
    Sun Sentinel Editorial Board, Sun Sentinel, 8 May 2026
  • Culturally, the word is synonymous with ugly, not just for the ways lesbians defy traditional gender roles in the popular imagination but for their disinclination toward and unavailability to men.
    Literary Hub, Literary Hub, 7 May 2026
Adjective
  • The soil may contain pathogens, pesticides and other unhealthful things.
    Joan Morris, Mercury News, 9 Feb. 2026
  • The change comes amid concerns about fireworks causing unhealthful air.
    Rong-Gong Lin II, Los Angeles Times, 19 June 2025
Adjective
  • Environmental officials documented no adverse effects on plant or animal life during the two-week display.
    Jeff Kleinman, Miami Herald, 9 May 2026
  • Part of the 5th Circuit’s rationale for reinstating the in-person requirement was the fact that the FDA eliminated mandatory reporting of adverse events associated with the drug.
    Theresa Gaffney, STAT, 8 May 2026

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Cite this Entry

“Noxious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/noxious. Accessed 14 May. 2026.

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