harmful

adjective

harm·​ful ˈhärm-fəl How to pronounce harmful (audio)
: of a kind likely to be damaging : injurious
harmfully adverb
harmfulness noun

Examples of harmful in a Sentence

DDT has been proven to be extremely harmful to the environment.
Recent Examples on the Web
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.
These are among the many casualties of the Trump administration's decision to level a research agency that has devoted much of its energy over the past five decades to reducing people's exposure to harmful chemicals and other dangerous conditions in the workplace. Will Stone, NPR, 2 May 2025 Along the way, it is divulged that Saw has not been protecting himself with a gas mask from the harmful rhydonium fumes. Dalton Ross, EW.com, 2 May 2025 Build Proprietary Products Instead Of Selling Raw Data Direct data sales offer quick cash but come with limited long-term gain (and potentially harmful downsides). Expert Panel®, Forbes.com, 1 May 2025 Funds for some projects that acknowledge some of America’s harmful wartime operations in Vietnam are flowing again after being put on hold during a 90-day evaluation period. Anna Mulrine Grobe, Christian Science Monitor, 30 Apr. 2025 See All Example Sentences for harmful

Word History

First Known Use

14th century, in the meaning defined above

Time Traveler
The first known use of harmful was in the 14th century

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Cite this Entry

“Harmful.” Merriam-Webster.com Dictionary, Merriam-Webster, http://www.merriam-webster.com/dictionary/harmful. Accessed 11 May. 2025.

Kids Definition

harmful

adjective
harm·​ful ˈhärm-fəl How to pronounce harmful (audio)
: causing damage : injurious
harmfully adverb
harmfulness noun

Legal Definition

harmful

adjective
harm·​ful
: of a kind likely to cause harm
harmfully adverb
harmfulness noun

More from Merriam-Webster on harmful

Last Updated: - Updated example sentences
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