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 He was charged with reckless endangerment, assault, and unlawful possession of noxious matter, the police said on Sunday. Claire Carter, The Washington Examiner, 8 Mar. 2026 Ian McGinnis, 21, of Philadelphia, was charged with assault, reckless endangerment and possession of a noxious material (pepper spray). Tom Ignudo, CBS News, 8 Mar. 2026 Depending on the adjusted last frost, be prepared to tackle crabgrass and other noxious weeds a week to two weeks earlier or later than in previous years. Nadia Hassani, The Spruce, 3 Mar. 2026 After DeSantis’ election, the relationship between Eikenberg and Van Lent metastasized, creating a noxious atmosphere for the science team. Michael Adno, Rolling Stone, 3 Mar. 2026 See All Example Sentences for noxious
Recent Examples of Synonyms for noxious
Adjective
  • For animals with severe toxicities, dialysis can be used to treat kidney failure as well as to extract poisonous substances from the blood, preventing further damage.
    The Washington Post, San Diego Union-Tribune, 14 Mar. 2026
  • If the flowers of sweet almond trees are pollinated with pollen from their bitter almond cousins, the resulting nuts are likely to be poisonous.
    Joshua Siskin, Oc Register, 14 Mar. 2026
Adjective
  • This method takes too long—by the time the soup is fully thawed, there is a high risk that harmful bacteria have already grown.
    Riley Wofford, Martha Stewart, 16 Mar. 2026
  • This can introduce impurities or harmful microorganisms to the bathroom environment as a result.
    Ethan Stone, USA Today, 15 Mar. 2026
Adjective
  • Most residents of the United Arab Emirates are South Asians, most of whom have come not for disgusting luxury but for comfortable, middle-class dignity that would be difficult to obtain in their home countries.
    Graeme Wood, The Atlantic, 15 Mar. 2026
  • On the phone, Miranda admits she’s known for a week, but agrees that what Shinia did was disgusting.
    Kathleen Walsh, Vulture, 14 Mar. 2026
Adjective
  • Some plants are entirely toxic while only the leaves, fruits or flowers of a plant cause problems.
    Caron Golden, San Diego Union-Tribune, 21 Mar. 2026
  • Maybe that’s because things behind the scenes were reportedly toxic as well.
    Rick Porter, HollywoodReporter, 21 Mar. 2026
Adjective
  • The private weather service AccuWeather calculated that more than 200 million people were under threat Monday of some kind of dangerous weather.
    Arkansas Online, Arkansas Online, 17 Mar. 2026
  • Prominent quartz slab makers acknowledge that processing produces dangerous dust, but claim risks are avoidable.
    Ethan Baron, Mercury News, 16 Mar. 2026
Adjective
  • This game started ugly, but the Jayhawks built a 38-18 halftime lead on the back of their defense.
    Shreyas Laddha, Kansas City Star, 21 Mar. 2026
  • Pushing too much hostility between team members or pushing Anthony too hard to be the peacekeeper could easily create an ugly atmosphere that spoils the vibe.
    Ben Travers, IndieWire, 20 Mar. 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
  • So borrowers who want to lock in a low mortgage rate may want to consider their options now, before any adverse conditions result in an increase.
    Matt Richardson, CBS News, 19 Mar. 2026
  • Other provisions require federal agencies to report the job effects of AI, and for the Department of Energy to collect data on the likelihood of adverse AI incidents.
    Ted Johnson, Deadline, 18 Mar. 2026

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Cite this Entry

“Noxious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/noxious. Accessed 22 Mar. 2026.

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