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 Pasteurization is the process of heating milk to a high enough temperature for a long enough time to kill harmful germs, according to the Centers for Disease Control and Prevention. Mary Walrath-Holdridge, USA TODAY, 3 May 2024 Additionally, more sea ice is melting in the Antarctic due to global warming, making the ozone hole more harmful, the study authors note. Will Sullivan, Smithsonian Magazine, 2 May 2024 See all Example Sentences for harmful 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'harmful.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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

Dictionary Entries Near harmful

Cite this Entry

“Harmful.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/harmful. Accessed 6 May. 2024.

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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