harm·​ful | \ ˈhärm-fəl How to pronounce harmful (audio) \

Definition of harmful

: of a kind likely to be damaging : injurious

Other Words from harmful

harmfully \ ˈhärm-​fə-​lē How to pronounce harmful (audio) \ 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 Scorsese infamously compared Marvel movies to theme park rides while discussing how superhero movies have reshaped exhibition in a way that’s harmful to non-superhero movies. Zack Sharf, Variety, 9 May 2022 Still, the practice has long been identified as harmful. Jackie Mader, NBC News, 7 May 2022 Turner, who is currently expecting her second child with husband Joe Jonas, said being a public figure played a role in the development of her negative self-image, calling out social media specifically as harmful to her mental health. Serena Coady, SELF, 6 May 2022 He also was charged with four counts of dealing in materials harmful to a minor, third-degree felonies; and one count of lewdness involving a child, a class A misdemeanor. Scott D. Pierce, The Salt Lake Tribune, 5 May 2022 Such action at this time would, in our view, be counterproductive, harmful to US trade policy, and unnecessary. Baker Institute, Forbes, 2 May 2022 Yet relatively few biologists—and hardly anyone else—are more than faintly aware of parasites beyond the tiny sliver of species such as tapeworms, pinworms and hookworms that are irksome or harmful to humans. Rachel Nuwer, Scientific American, 28 Apr. 2022 Congress is under pressure to act following recent disclosures of content potentially harmful to young people on social-media sites including Facebook, Instagram and TikTok. John D. Mckinnon, WSJ, 26 Apr. 2022 If anybody could afford to leave some money on the table to make a social network less harmful to public discourse, it’s Elon Musk. Timothy B. Lee, Ars Technica, 26 Apr. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'harmful.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of harmful

14th century, in the meaning defined above

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

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Last Updated

21 May 2022

Cite this Entry

“Harmful.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/harmful. Accessed 26 May. 2022.

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More Definitions for harmful


harm·​ful | \ ˈhärm-fəl How to pronounce harmful (audio) \

Kids Definition of harmful

: causing or capable of causing harm Keep harmful substances away from children.

Other Words from harmful

harmfully \ -​fə-​lē \ adverb



Legal Definition of harmful

: of a kind likely to cause harm

Other Words from harmful

harmfully adverb
harmfulness noun

More from Merriam-Webster on harmful

Nglish: Translation of harmful for Spanish Speakers

Britannica English: Translation of harmful for Arabic Speakers


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