harmful

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

Definition of harmful

: of a kind likely to be damaging : injurious

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Other Words from harmful

harmfully \ ˈhärm-​fə-​lē How to pronounce harmfully (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

While the bill ultimately saw several changes pushed by gun-advocacy groups, the new legislation would enable households to join the effort to prevent potentially harmful behavior. Jerome Campbell, BostonGlobe.com, "DeLeo endorses ‘red flag’ bill to temporarily seize guns if owner poses a threat," 3 May 2018 In addition to reinforcing gender stereotypes, that type of talk can actually be harmful. Tamekia Reece, Good Housekeeping, "An Age-by-Age Guide to Raising Boys, According to Child Development Experts," 30 Apr. 2019 Moreover, like all active drugs, marijuana can be harmful if used incorrectly. WSJ, "Marijuana Health Benefits Need More Study," 29 Jan. 2019 The number of new U.S. measles cases continued to accelerate last week as health authorities race to curb the outbreaks and scientists who study the virus say measles may be more harmful than once believed. Betsy Mckay, WSJ, "Measles Cases Continue to Soar, Stirring Concern Over Long-Term Effects," 15 Apr. 2019 Alcohol is viewed fondly by much of the population, despite being more harmful than cannabis by almost any measure. Amber Senter, Marie Claire, "We Have to Acknowledge That CBD Use Is a Privilege," 11 Apr. 2019 And even if these off-target mutations aren’t harmful, research has shown that a mutation in the CCR5 gene can make people more susceptible to dying from the flu. Angela Chen, The Verge, "Flawed DNA editing of alleged ‘designer babies’ may have put their health at risk," 29 Nov. 2018 Advertising Of immediate concern is whether warmer water will allow harmful algae containing toxins to stay viable long enough for shellfish to eat them and pass toxins to marine mammals and people. Dan Joling, The Seattle Times, "Pace of Bering Sea changes startles scientists," 16 Apr. 2019 While the magnetosphere shields Earth from the harmful radiation within these particles, giant blobs of them can create disturbances that interfere with satellites and communications signals. David Grossman, Popular Mechanics, "How a Second Look At 40-Year-Old Studies Helped Explain Solar Wind," 6 Apr. 2019

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.

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First Known Use of harmful

14th century, in the meaning defined above

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Dictionary Entries near harmful

harm's way

harman

harmattan

harmful

harmless

Harmolita

harmonia

Statistics for harmful

Last Updated

10 Jun 2019

Look-up Popularity

Time Traveler for harmful

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

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More Definitions for harmful

harmful

adjective

English Language Learners Definition of harmful

: causing or capable of causing damage or harm

harmful

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

Kids Definition of harmful

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

Other Words from harmful

harmfully \ -​fə-​lē \ adverb

harmful

adjective
harm·​ful

Legal Definition of harmful

: of a kind likely to cause harm

Other Words from harmful

harmfully adverb
harmfulness noun

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More from Merriam-Webster on harmful

Thesaurus: All synonyms and antonyms for harmful

Spanish Central: Translation of harmful

Nglish: Translation of harmful for Spanish Speakers

Britannica English: Translation of harmful for Arabic Speakers

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