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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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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 Decaying sargassum poses health risks, emits noxious gases, and smothers marine habitats and tourist beaches alike, underscoring a cascading set of environmental and economic challenges well beyond the Caribbean islands. Sophie Clark, MSNBC Newsweek, 6 June 2025 That combination of higher prices, uncertainty and pessimism can be outright noxious as pullbacks in consumer and business spending can have cascading negative effects on the labor market and the broader economy. Alicia Wallace, CNN Money, 1 June 2025 Listen to this article A program that has shown remarkable success at controlling a noxious, invasive weed choking the lower Connecticut River is on hold at least temporarily because of funding cuts by the federal government. Edmund H. Mahony, Hartford Courant, 12 May 2025 The university paid back taxes, lost its exemption, and continued its noxious policy against students interracially dating and marrying until the school’s leadership finally came to its senses and publicly disavowed the policy in 2000. Marie Sapirie, Forbes.com, 12 May 2025 See All Example Sentences for noxious
Recent Examples of Synonyms for noxious
Adjective
  • Also, maybe, Regan, the king’s poisonous middle daughter.
    Han Ong, New Yorker, 22 June 2025
  • In addition to cyanide in her water, poisonous powder was also put in her air vents, prosecutors said.
    Kate Linderman, Kansas City Star, 20 June 2025
Adjective
  • Research has found that building roads can fragment habitats, disrupt ecosystems, and increase erosion and sediment pollution in drinking water, among other potentially harmful outcomes.
    Hayley Smith, Los Angeles Times, 24 June 2025
  • This kind of leadership without empathy is not only unsustainable but actively harmful to morale and performance.
    Jody Michael, Forbes.com, 23 June 2025
Adjective
  • First came the disgusting pictures of waters so fouled that they were often compared to rotting guacamole.
    Orlando Sentinel Editorial Board, The Orlando Sentinel, 26 June 2025
  • Republicans seem to try to outdo each other to see who can be the most hateful and disgusting.
    Sun Sentinel Editorial Board, Sun Sentinel, 26 June 2025
Adjective
  • That’s the best way to describe how the Boys in Blue have acted as the city emblazoned on their hats and road jerseys battles Donald Trump’s toxic alphabet soup of federal agencies that have conducted immigration sweeps across Los Angeles over the past two weeks.
    Gustavo Arellano, Los Angeles Times, 21 June 2025
  • Multiple residents near New York Avenue in Whiting did not know about the EPA’s plans to test the area for toxic soil.
    Meredith Colias-Pete, Chicago Tribune, 20 June 2025
Adjective
  • And here, the country is experiencing a profound—and dangerous—shift.
    ASHLEY J. TELLIS, Foreign Affairs, 17 June 2025
  • This vulnerability becomes even more dangerous in moments of crisis.
    Kurt Knutsson, FOXNews.com, 17 June 2025
Adjective
  • The wild and ugly scenes saw rioters attack law enforcement with rocks and Molotov cocktails while others burned vehicles and other property.
    Michael Dorgan, FOXNews.com, 28 June 2025
  • The pair hit an ugly double-spinebuster on the Arabic announce table.
    Alfred Konuwa, Forbes.com, 28 June 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
  • Risks and precautions Research has shown that NSAIDs have multiple adverse effects and should be used with caution, both doctors pointed out.
    Khloe Quill, FOXNews.com, 18 June 2025
  • Hall’s Visual Language Access and Acquisition Lab is a leader in researching those adverse effects and possible solutions.
    Alan Schwarz, Forbes.com, 17 June 2025

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Cite this Entry

“Noxious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/noxious. Accessed 2 Jul. 2025.

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