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harmful

adjective

harm·​ful ˈhärm-fəl How to pronounce harmful (audio)
Synonyms of harmfulnext
: of a kind likely to be damaging : injurious
harmful chemicals
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.
Critics argued that his latest statements not only normalized harmful language but also attempted to shift blame to other streamers without evidence. Preezy Brown, VIBE.com, 1 Dec. 2025 This reusable beeswax wrap offers the same convenience of protecting your foods without the potential harmful effects of PVC. Alicia Geigel, Southern Living, 1 Dec. 2025 Scientists wanted to better understand whether abdominal fat — the kind stored deep around internal organs — is more harmful to the heart than general body fat. Khloe Quill, FOXNews.com, 1 Dec. 2025 Newer studies have revealed that eggs are not necessarily harmful as experts once thought. Colleen Doherty, Verywell Health, 1 Dec. 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

Browse Nearby Words

Cite this Entry

“Harmful.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/harmful. Accessed 4 Dec. 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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