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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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 Theroux attempts to speak with women connected to his noxious subjects, but his efforts are largely thwarted. Alison Foreman, IndieWire, 19 Mar. 2026 Idaho’s pest management programs traditionally deal with agrarian problems, like noxious weeds, or agricultural raiders like pocket gophers, marmots or voracious insects. Mark Dee march 17, Idaho Statesman, 17 Mar. 2026 Imagery from Landsat taken on Monday showed a fire at Dubai International Airport after an Iranian drone strike set a fuel tanker ablaze at the world’s busiest airport for international travel, causing a plume of noxious black smoke. Jon Gambrell, Chicago Tribune, 17 Mar. 2026 First, a bunch of noxious social-media posts surfaced in which Platner had committed all manner of racist, sexist, and equal-opportunity offenses. Mark Leibovich, The Atlantic, 16 Mar. 2026 See All Example Sentences for noxious
Recent Examples of Synonyms for noxious
Adjective
  • The whisky was slightly poisonous.
    AJ Willingham, AJC.com, 6 Apr. 2026
  • Marsha purchased the ingredients for this poisonous beverage at a local store.
    Peter Van Sant, CBS News, 5 Apr. 2026
Adjective
  • This week, California regulators are taking a critical look at one of the state’s most harmful laws.
    Tom Manzo, Oc Register, 6 Apr. 2026
  • Awareness, not alarm, is a powerful tool for families navigating online spaces where harmful language and intent are often hidden in plain sight.
    Sharlette A. Kellum, The Conversation, 6 Apr. 2026
Adjective
  • Living under an openly misogynistic president may have felt freakish in 2017, but by his second term, bigotry became yet another disgusting norm.
    Ben Travers, IndieWire, 2 Apr. 2026
  • The amount of disrespect shown the Broncos is disgusting.
    Troy Renck, Denver Post, 27 Mar. 2026
Adjective
  • Spinosad, although organically certified, can be toxic to bees, and pyrethrins—derived from plants—can affect a wide range of insects.
    Anthony Reardon, Kansas City Star, 4 Apr. 2026
  • For the outdoors, look to non-toxic and chemical-free (or chemical-lite) sprays.
    Alora Bopray, USA Today, 4 Apr. 2026
Adjective
  • The sheriff's office extended condolences to the child's family and loved ones, calling the incident a tragic reminder of how quickly conditions on the water can turn dangerous.
    Richard Ramos, CBS News, 7 Apr. 2026
  • As multiple cities around Jackson County move to ban types of unregulated and potentially dangerous ‘gas station drugs’ — specifically more potent variations of kratom — Lee’s Summit has not only joined the charge but has taken restrictions even further.
    Ilana Arougheti, Kansas City Star, 6 Apr. 2026
Adjective
  • While not the pastor of the United States, Trump surely represents the face of the United States on a daily basis, and that face is an ugly one.
    Chicago Tribune, Chicago Tribune, 9 Apr. 2026
  • Featuring the good, the bad and the ugly, ‘Look of the Week’ is a regular series dedicated to unpacking the most talked about outfit of the last seven days.
    Leah Dolan, CNN Money, 9 Apr. 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
  • The most common adverse events were falls and muscle weakness, which overlap with ALS symptoms.
    Angelica Stabile, FOXNews.com, 3 Apr. 2026
  • When you're stressed or angry, your cortisol levels rise, which can have adverse effects on your heart, metabolism, and immune system.
    Sharon Basaraba, Verywell Health, 3 Apr. 2026

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Cite this Entry

“Noxious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/noxious. Accessed 11 Apr. 2026.

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