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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 Even on Etna’s quieter days, the summit terrain is a minefield of loose rock, sharp edges, and noxious gases. Erica Firpo, AFAR Media, 4 June 2025 That is, whether people would lose the ability to sense when their body is experiencing a noxious stimuli, if enough of those stimuli are paired with a pleasurable reward. Peter Ubel, Forbes.com, 10 June 2025 Cons: Green methanol has a lower flash point than diesel fuel, and the vapors are noxious. Nathan Diller, USA Today, 10 June 2025 Those who live near the Chiquita Canyon landfill have come to depend on the guidance of state scientists monitoring the noxious fumes coming off the literal dumpster fire. William Melhado, Sacbee.com, 5 June 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
  • Setting the right tone and removing toxic employees becomes mission-critical to managing human employees in an age of AI.
    Jennifer C. Wolfe, Forbes.com, 2 July 2025
  • The full moon in Libra on the 12th illuminates your relationships, highlighting where you may be stuck in codependent or toxic dynamics.
    Meghan Rose, Glamour, 1 July 2025
Adjective
  • And the Santa Barbara temblor revealed just how dangerous brick buildings built in that era could be.
    Rong-Gong Lin II, Los Angeles Times, 29 June 2025
  • After landing, the most dangerous times, statistically speaking, are takeoff, approach, and initial climb.
    Katie Jackson, Travel + Leisure, 29 June 2025
Adjective
  • The pair hit an ugly double-spinebuster on the Arabic announce table.
    Alfred Konuwa, Forbes.com, 28 June 2025
  • 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
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 other four are: Columbus, New Mexico, on July 14 Santa Teresa, New Mexico, on July 21 Del Rio, Texas, on August 18 Laredo, Texas, on September 15 Each reopening will be evaluated for adverse effects before proceeding to the next phase.
    Adeola Adeosun, MSNBC Newsweek, 1 July 2025
  • Then, notify the FDA MedWatch adverse event program.
    David J. Neal, Miami Herald, 30 June 2025

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Cite this Entry

“Noxious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/noxious. Accessed 7 Jul. 2025.

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