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 In a decentralized system, managing harmful or inappropriate content becomes more complex, potentially leading to a rise in cyberbullying, misinformation and other harmful activities. Jeffrey Edell, Rolling Stone, 3 July 2024 Raw or undercooked beef can contain harmful, illness-causing bacteria. Clare Mulroy, USA TODAY, 3 July 2024 Common symptoms of ingesting a harmful strain of E. coli include vomiting and diarrhea. Chad De Guzman, TIME, 2 July 2024 Reviewers are big fans of the stretchy, soft fabric, which also protects your skin from the sun’s harmful UV rays. Kristin Canning, SELF, 2 July 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 15 Jul. 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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