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

Relevance

Antonyms & Near Antonyms

2
3

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 Over time, however, the culture on the ground became just as noxious as Ye’s most unhinged instincts. Jeff Ihaza, Rolling Stone, 31 Mar. 2026 But some of the worst invaders are actually noxious weeds, which can be directly harmful to humans, livestock, pets, and wildlife. Natalie Krebs, Outdoor Life, 26 Mar. 2026 Orson Scott Card wrote a whole series preoccupied with the devastating results of interspecies misunderstanding and intolerance, then followed it up with various noxious statements cementing his homophobia. Sara Holdren, Vulture, 24 Mar. 2026 Theroux attempts to speak with women connected to his noxious subjects, but his efforts are largely thwarted. Alison Foreman, IndieWire, 19 Mar. 2026 See All Example Sentences for noxious
Recent Examples of Synonyms for noxious
Adjective
  • Restoring the balance of the humors through profusely bleeding the patient or inducing vomiting or diarrhea with the poisonous plant hellebore.
    Literary Hub, Literary Hub, 28 Apr. 2026
  • There’s a steadiness to Tung/Wonder Woman that stands out for its quiet authority in a frequently goofy landscape peppered with poisonous robes and finger-eating minions.
    Sarah Shachat, IndieWire, 24 Apr. 2026
Adjective
  • But research has shown that several metabolic and heart diseases impair the immune system’s ability to moderate inflammation—causing harmful levels of inflammation in response to high cholesterol, fat or glucose.
    Lauren J. Young, Scientific American, 27 Apr. 2026
  • Today, 87% of agricultural subsidies are environmentally or socially harmful.
    Carlos Alvarado Quesada, Fortune, 27 Apr. 2026
Adjective
  • The water is disgusting-looking.
    Adam England, PEOPLE, 24 Apr. 2026
  • These words then take on guilt by association because of the things we have been socialized to find unpleasant, uncomfortable, or disgusting.
    Literary Hub, Literary Hub, 21 Apr. 2026
Adjective
  • They are filled with hateful bigotry and toxic and dangerous lies.
    Robert B. Reich, Hartford Courant, 25 Apr. 2026
  • The first fight between on-the-rocks elder millennials Josh (Oscar Isaac) and Lindsay (Carey Mulligan), witnessed by the young betrotheds Austin (Charles Melton) and Ashley (Cailee Spaeny), creates the toxic connection between the couples and sets off everything else that happens on the show.
    Sarah Shachat, IndieWire, 24 Apr. 2026
Adjective
  • The procedures noted that in some cases, outing students to parents could be dangerous to their health and well-being, and school officials should ask the students for consent to notify their parents of the support plan.
    Melissa Quinn, CBS News, 27 Apr. 2026
  • The world is more dangerous for leaders, across multiple dimensions.
    Diane Brady, Fortune, 27 Apr. 2026
Adjective
  • As their mutual competitiveness grows shockingly ugly, Niall learns to turn Ruben’s Samsonian strength and fury against him, knocking down the pillars of Ruben’s own life.
    Inkoo Kang, New Yorker, 24 Apr. 2026
  • Rudy Gobert followed his inspired Game 2 effort against Nikola Jokic by stifling the three-time MVP again on an ugly 7-for-26 shooting night, and the Timberwolves established a postseason franchise record by allowing the Nuggets just 11 points in the tone-setting first quarter.
    CBS News, CBS News, 24 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
  • Additionally, there were no serious adverse effects reported.
    Stephanie Pappas, Scientific American, 24 Apr. 2026
  • There were no concerns over safety or adverse events.
    Beth Mole, ArsTechnica, 24 Apr. 2026

Browse Nearby Words

Cite this Entry

“Noxious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/noxious. Accessed 1 May. 2026.

More from Merriam-Webster on noxious

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster