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 The skin barrier is composed of lipids (fats), proteins, and other substances that help maintain hydration and prevent harmful substances from getting in. Amanda Gardner, Health, 4 Mar. 2024 Ultimately, the prevalence of this pattern suggests its utility as a natural strategy for ridding the stomach of harmful substances. Melissa Cristina Márquez, Forbes, 2 Mar. 2024 Read on to learn why some lubes can be harmful while trying to conceive, what to look for in sperm-friendly fertility lubricant, plus what to avoid. Nicole Harris, Parents, 2 Mar. 2024 The downside is that their speech can be hateful, harassing, false and harmful in other ways. Erwin Chemerinsky, The Mercury News, 1 Mar. 2024 In a statement, YouTube referred NBC News to the company’s policies for content pertaining to harmful substances and medical misinformation. Katie Mogg, NBC News, 29 Feb. 2024 Vaccines prevent not only many illnesses that can spread from animals to humans, but also diseases limited to the animal but that could be harmful and even fatal. Katia Hetter, CNN, 29 Feb. 2024 The company tried to compensate for the biases that commonly occur in image generators due to the presence of harmful cultural stereotypes in the images used to train them, many of which are generally sourced from the web and show a white, Western bias. Will Knight, WIRED, 29 Feb. 2024 The harmful pollutant has leached into water in many parts of the valley from sources including fertilizers, dairies and septic tanks. Ian James, Los Angeles Times, 20 Feb. 2024

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 19 Mar. 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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