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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 Delivering drugs to the brain The blood-brain barrier is evolution’s exquisite solution to keeping noxious substances away from this most critical organ. Richard J. Price, The Conversation, 15 Oct. 2025 So truly noxious fart sprays often contain secret ingredient blends that are difficult to evaluate. Nate Anderson, ArsTechnica, 25 Sep. 2025 The hijacking of the sport and the community institutions that built it, by noxious forces using it for their own means. Nick Miller, New York Times, 24 Sep. 2025 Now though, there’s little safe haven in independent art either, where podcasting and comedy have welcomed truly noxious voices that are eager to remake themselves as Wormtongues in the halls of power. James Folta september 19, Literary Hub, 19 Sep. 2025 See All Example Sentences for noxious
Recent Examples of Synonyms for noxious
Adjective
  • For all their sophistication—transforming a poisonous root and its leaves into a whole range of delicacies is no mean feat—for years such dishes were seen by the city’s elite as the food of poverty.
    Michael Snyder, Travel + Leisure, 5 Nov. 2025
  • By appointing a man who was deeply unpopular with fans by the end of his reign so recently, though, Wolves would have been condemning him and his players to working in a poisonous environment from day one.
    Steve Madeley, New York Times, 3 Nov. 2025
Adjective
  • Specialty cleaners made for glass cooktops don’t contain harmful ingredients like ammonia.
    Karen Brewer Grossman, Southern Living, 5 Nov. 2025
  • Small settings changes can make a big difference in reducing exposure to harmful or suggestive content.
    Kurt Knutsson, FOXNews.com, 5 Nov. 2025
Adjective
  • By modern standards, kind of disgusting.
    Glenn Garner, Deadline, 7 Nov. 2025
  • But stepping into that closet was really disgusting.
    Lauren Huff, Entertainment Weekly, 31 Oct. 2025
Adjective
  • No politician will want to be associated with a team that is now toxic.
    Fort Worth Star-Telegram, Fort Worth Star-Telegram, 11 Nov. 2025
  • King invented The Network at a time when people were still processing the toxic relationship between mass entertainment and mind control, and while the thrust of his story may not have aged a day, the medium is the message, and that medium has changed.
    David Ehrlich, IndieWire, 11 Nov. 2025
Adjective
  • Chicago is facing a dangerous lake-effect snow event early Monday morning.
    Briana Waxman, CNN Money, 10 Nov. 2025
  • Two decades ago, when the NFL's base offense consisted of two backs with a blocking tight end and only two wide receivers, an elite cornerback could often take away half of the dangerous receiving options.
    Mike Sando, New York Times, 10 Nov. 2025
Adjective
  • This was one of the ugliest matches in recent memory; a game that, in isolation, only those fond of trench warfare could love.
    Jacob Whitehead, New York Times, 10 Nov. 2025
  • Things got a little ugly for Pretty Little Liars star Shay Mitchell this week.
    Raechal Shewfelt, Entertainment Weekly, 8 Nov. 2025
Adjective
  • The change comes amid concerns about fireworks causing unhealthful air.
    Rong-Gong Lin II, Los Angeles Times, 19 June 2025
  • Health professionals encourage people to use lean cuts of meat because most of the fat in animal products is unhealthful saturated fat, which can raise the risk of heart disease and cancer.
    Bethany Thayer, Detroit Free Press, 22 June 2024
Adjective
  • Because obesity will drive higher blood pressure, higher blood sugar, more adverse cholesterol levels—all sorts of things—that sort of becomes a perfect storm.
    Veronique Greenwood, Time, 6 Nov. 2025
  • These weather conditions will result in elevated fire potential and a threat of adverse fire behavior.
    NC Weather Bot, Charlotte Observer, 5 Nov. 2025

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Cite this Entry

“Noxious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/noxious. Accessed 14 Nov. 2025.

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