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.
Working out prior to menopause will reduce the risk of osteoporosis in your later years. And avoid harmful habits – smoking and heavy alcohol consumption can weaken bone density and increase the risk of fractures. Jianying Zhang, Discover Magazine, 8 Nov. 2024 Albanese cited the risks to the physical and mental health of children from excessive social media use, in particular the risks to girls from harmful depictions of body image and misogynist content aimed at boys. Reuters, NBC News, 7 Nov. 2024 These remedies are incomplete at best and harmful at worst. Thomas G. Moukawsher, Newsweek, 5 Nov. 2024 This may include protecting people’s privacy, mitigating harmful biases, improving transparency or reducing environmental impact—a very hot topic in the news recently. Eric Miquelon, Forbes, 5 Nov. 2024 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

Dictionary Entries Near harmful

Cite this Entry

“Harmful.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/harmful. Accessed 26 Nov. 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
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!