noxious
Americanadjective
-
harmful or injurious to health or physical well-being.
noxious fumes.
- Synonyms:
- deleterious, detrimental, nocuous, unhealthy, unwholesome, hurtful
- Antonyms:
- harmless
-
morally harmful; corrupting; pernicious.
a noxious plan to spread dissension.
- Synonyms:
- corruptive
- Antonyms:
- harmless
adjective
-
poisonous or harmful
-
harmful to the mind or morals; corrupting
Other Word Forms
Etymology
Origin of noxious
1605–15; < Latin noxius harmful, hurtful, injurious, equivalent to nox ( a ) harm, hurt, injury (akin to nocēre to do harm, inflict injury; see innocent) + -ius -ious
Explanation
Something noxious is harmful and could be even fatal — whether it is colorless, odorless, and invisible like carbon monoxide, or dark, strong-smelling, and obvious, like black smoke from a fire. People are called noxious too when they hurt others with cruelty or mental anguish. English and Latin roots for noxious are related to the meanings of "harm," "damage," and "injury." While obnoxious might come to mind when seeing the word noxious, obnoxious is a much less damaging adjective to describe someone annoying. Most uses for noxious involve real physical or emotional damage unless the word is used in exaggeration. Examples range from "the noxious gas fumes made the dog pass out" to "his cologne was so noxious I had to exit the elevator and take the stairs."
Vocabulary lists containing noxious
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Residents say the notices represent just a fraction of what occurs at the site, including noxious odors and noisy truck deliveries when people are trying to sleep.
From Los Angeles Times ● Oct. 3, 2026
These companies could solve a majority of their issues by slowing down the AI-infrastructure arms race and spending extra to build more modern, less noxious data centers.
From The Wall Street Journal ● Sep. 4, 2026
A June 17 fire at cold storage operator Lineage’s 500,000-square-foot food warehouse left the community with noxious smoke and an influx of rats and flies attracted to rotting meat.
From Los Angeles Times ● Sep. 1, 2026
Controversial decisions, threats to officials, a noxious atmosphere culminating with Celtic fans squaring up to Hearts players - it was a pitiful end to what been a thrilling season.
From BBC ● Jul. 31, 2026
Two days after leaving Venice, Hazel still couldn’t get the noxious scent of eau de cow monster out of her nose.
From "The House of Hades" by Rick Riordan
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Get a wordDefinitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
