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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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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 Some of the noxious spray also hit the little girl in her face and arm. Roni Jacobson, New York Daily News, 27 June 2025 State law specifically names these three plants as noxious weeds: Municipalities can add to this list based on recommendations from the Wisconsin Department of Natural Resources' invasive species list. Quinn Clark, jsonline.com, 25 July 2025 While seven out of 10 Indians are exposed to noxious air, pregnant women and their unborn children are among the most impacted. Anuradha Varanasi, Forbes.com, 23 July 2025 Though Indian boarding schools still forcibly sheared children’s hair, Jones’s orders for adult men proved too noxious to enforce. Margaret Talbot, New Yorker, 21 July 2025 See All Example Sentences for noxious
Recent Examples of Synonyms for noxious
Adjective
  • If touched, the toad’s poisonous glands emit toxins that can be rapidly absorbed in your dog’s bloodstream and kill her quickly.
    Lois K. Solomon, Sun Sentinel, 8 Aug. 2025
  • While every season is different depending on the location, some of the past challenges have included walking across a tightrope over a cliff, rescuing themselves from a sinking car and invading a crate filled with poisonous gases and chemicals.
    Caroline Blair, People.com, 7 Aug. 2025
Adjective
  • In a time when transgender rights are under threat via a backlash spurred on by harmful theology within church spaces, the call for inclusion — despite one’s gender identity, expression, or sexuality — is both a rarity and necessity within the traditional gospel and Christian world.
    Meagan Jordan, Rolling Stone, 8 Aug. 2025
  • These tools can help detect harmful symbols, explicit imagery or copyright violations before content is published.
    Anees Ali Khan, Forbes.com, 8 Aug. 2025
Adjective
  • Kruse and her co-conspirators are now on their fourth different set of lawyers in this dispute, and this is a disgusting publicity stunt by new counsel, as evidenced by the fact that the complaint and press release were sent to the press before the complaint was served.
    Michaela Zee, Variety, 13 Aug. 2025
  • The series sets the various human and humanoid segments of its cast on a direct course with the distinctly inhuman alien flora and fauna on the ship – there are some inventive little monsters aboard, disgusting and harrowing in their own special ways – to great effect.
    Kelly Lawler, USA Today, 12 Aug. 2025
Adjective
  • This is significant because melittin alone is highly toxic and can damage healthy tissues if not carefully controlled.
    Jasmine Laws, MSNBC Newsweek, 5 Aug. 2025
  • The dangers of breathing wildfire smoke Wildfires burn at extremely high temperatures, which makes their ash more toxic than other pollution, such as car exhaust.
    Alejandra Borunda, NPR, 4 Aug. 2025
Adjective
  • That said, the Revolution had promising spells of attacking play and even looked the more dangerous side in the first half.
    Julian Cardillo, Boston Herald, 17 Aug. 2025
  • In hilly terrain there are hundreds of low water crossings which are potentially dangerous in heavy rain.
    NC Weather Bot, Charlotte Observer, 16 Aug. 2025
Adjective
  • In the ugliest defeat of a season belatedly compiling them, the New York Mets blew an early 6-0 lead Wednesday to fall to the Atlanta Braves 11-6.
    Tim Britton, New York Times, 14 Aug. 2025
  • The Navy must address the ugly fact that, despite all the security America can provide, a diverse array of enemies, rivals and criminals can shut the Panama Canal down at virtually any time.
    Craig Hooper, Forbes.com, 14 Aug. 2025
Adjective
  • The change comes amid concerns about fireworks causing unhealthful air.
    Rong-Gong Lin II, Los Angeles Times, 19 June 2025
  • The unhealthful effects of autocracy remain robust even when accounting for economic differences and when excluding Venezuela and its collapsing health-care system.
    Thomas J. Bollyky, Foreign Affairs, 30 Jan. 2020
Adjective
  • The maintenance of a favorable risk-reward ratio over a shorter timeframe of 5 years is promising for retirement accounts – mitigating the risk of liquidation (if necessary) during adverse drawdown scenarios.
    Trefis Team, Forbes.com, 14 Aug. 2025
  • Many models struggle to operate in adverse weather conditions, and drones have weight limits for parcels.
    Meghan Hall, Sourcing Journal, 14 Aug. 2025

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Cite this Entry

“Noxious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/noxious. Accessed 21 Aug. 2025.

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