1
a
: physically harmful or destructive to living beings
noxious waste
noxious fumes
b
: constituting a harmful influence on mind or behavior
especially
: morally corrupting
noxious doctrines
2
: disagreeable, obnoxious
this noxious political scandal—
H. L. Ickes
H. L. Ickes
noxiously
adverb
noxiousness
noun
Examples of noxious in a Sentence
mixing bleach and ammonia can cause noxious fumes that can seriously harm you
noxious smog that for years has been encrusting the historic cathedral with soot
Recent Examples on the Web
Decaying sargassum poses health risks, emits noxious gases, and smothers marine habitats and tourist beaches alike, underscoring a cascading set of environmental and economic challenges well beyond the Caribbean islands.
—Sophie Clark, MSNBC Newsweek, 6 June 2025
That combination of higher prices, uncertainty and pessimism can be outright noxious as pullbacks in consumer and business spending can have cascading negative effects on the labor market and the broader economy.
—Alicia Wallace, CNN Money, 1 June 2025
Listen to this article A program that has shown remarkable success at controlling a noxious, invasive weed choking the lower Connecticut River is on hold at least temporarily because of funding cuts by the federal government.
—Edmund H. Mahony, Hartford Courant, 12 May 2025
The university paid back taxes, lost its exemption, and continued its noxious policy against students interracially dating and marrying until the school’s leadership finally came to its senses and publicly disavowed the policy in 2000.
—Marie Sapirie, Forbes.com, 12 May 2025
See All Example Sentences for noxious
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.
Sophie Clark, MSNBC Newsweek, 6 June 2025
That combination of higher prices, uncertainty and pessimism can be outright noxious as pullbacks in consumer and business spending can have cascading negative effects on the labor market and the broader economy.
—Alicia Wallace, CNN Money, 1 June 2025
Listen to this article A program that has shown remarkable success at controlling a noxious, invasive weed choking the lower Connecticut River is on hold at least temporarily because of funding cuts by the federal government.
—Edmund H. Mahony, Hartford Courant, 12 May 2025
The university paid back taxes, lost its exemption, and continued its noxious policy against students interracially dating and marrying until the school’s leadership finally came to its senses and publicly disavowed the policy in 2000.
—Marie Sapirie, Forbes.com, 12 May 2025
See All Example Sentences for noxious
Cite this Entry
“Noxious.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/noxious. Accessed 10 Jun. 2025.
Copy CitationKids Definition
noxious
adjective
nox·ious
ˈnäk-shəs 
: harmful especially to health : unwholesome
noxious fumes
Medical Definition
noxious
adjective
nox·ious
ˈnäk-shəs
: physically harmful or destructive to living beings
noxious wastes
Love words? Need even more definitions?
Merriam-Webster unabridged
Share