as in detrimental
causing or capable of causing harm
DDT has been proven to be extremely harmful to the environment
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Recent Examples of harmful
The research did not find any solid proof that elderberry causes harmful immune overreactions.
—
Julie Scott, Verywell Health, 26 Jan. 2026
Gmail hasn’t scanned this message for spam, unverified senders, or harmful software.
—David Phelan, Forbes.com, 25 Jan. 2026
People should avoid swimming when warnings are posted so as to reduce their exposure to harmful pathogens.
—Ethan Stone, Ascend Agency, 25 Jan. 2026
Avoid mixing cleaning vinegar with bleach, as this can produce harmful chlorine gas.
—Alexandra Kelly, Martha Stewart, 25 Jan. 2026
See All Example Sentences for harmful
Julie Scott, Verywell Health, 26 Jan. 2026
Gmail hasn’t scanned this message for spam, unverified senders, or harmful software.
—David Phelan, Forbes.com, 25 Jan. 2026
People should avoid swimming when warnings are posted so as to reduce their exposure to harmful pathogens.
—Ethan Stone, Ascend Agency, 25 Jan. 2026
Avoid mixing cleaning vinegar with bleach, as this can produce harmful chlorine gas.
—Alexandra Kelly, Martha Stewart, 25 Jan. 2026
See All Example Sentences for harmful
Recent Examples of Synonyms for harmful
Adjective
-
The opposite, overwatering, is also detrimental because the seeds may rot.—
Megan Hughes,
Better Homes & Gardens,
28 Jan. 2026
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There’s been tension between the dynamic guard and head coach Tuomas Iisalo and some of that started after the Grizzlies lost to the Lakers in October in which Morant scored only eight points and was later suspended for one game for conduct detrimental to the team for postgame comments.—
Broderick Turner,
Los Angeles Times,
28 Jan. 2026
Adjective
-
This is because free iron can catalyze reactive oxygen species, which may prove to be chemically damaging.—
Scott Travers,
Forbes.com,
30 Jan. 2026
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Emily Mendenhall traces the medical myths, gender bias, and neurological truths behind hysteria, one of history’s most damaging diagnoses.—
Big Think,
Big Think,
29 Jan. 2026
Adjective
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More than a billion phones are now ineligible for security updates at a time when the threat landscape has never been more dangerous.—
Zak Doffman,
Forbes.com,
27 Jan. 2026
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The church opened its warming center over the weekend, anticipating the arrival of the winter storm and the dangerous drop in temperatures.—
Leondra Head,
CBS News,
27 Jan. 2026
Adjective
-
Affected cosmetics that are applied to the skin or eyes may lead to skin irritation, infection, or other adverse reactions.—
Michele Laufik,
Martha Stewart,
30 Jan. 2026
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Even for women whose initial mammograms didn’t show any calcium buildup and were considered low risk, risk of an adverse cardiac incident increased by 41% if buildup was detected on followups.—
Helen Carefoot,
Flow Space,
30 Jan. 2026
Adjective
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Azzi Fudd scored 27 points and Sarah Strong added 26 to help UConn beat Tennessee, handing the Lady Vols their worst loss in the storied rivalry.—
Arkansas Online,
Arkansas Online,
2 Feb. 2026
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To that end, here’s a selection of the best (and most enjoyably bad) literary film and TV coming to streaming services this month.—
Emily Temple,
Literary Hub,
2 Feb. 2026
Cite this Entry
“Harmful.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/harmful. Accessed 6 Feb. 2026.
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