harmful

adjective
harm·ful | \ ˈhärm-fəl \

Definition of harmful 

: of a kind likely to be damaging : injurious

Keep scrolling for more

Other words from harmful

harmfully \ˈhärm-fə-lē \ 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

An article last Wednesday about a Maryland agricultural official who is training dogs to detect bacteria harmful to beehives misstated the breed of one dog, Mack. New York Times, "Corrections: July 11, 2018," 10 July 2018 People who engage in behaviours deemed harmful to the public good are those that the British authorities are obligated to deny entry to. SI.com, "The Mounting Uncertainty at Chelsea Has Seen the Club Relinquish Their Top 4 Birthright," 9 July 2018 Childhood developmental experts warn us about the harmful and lasting effects of early-age abandonment. Bea Lewis, Sun-Sentinel.com, "Understanding their cries | Opinion," 5 July 2018 According to research from Desentum, a biopharmaceutical research company, the body mistakes pollen as harmful and begins a series of steps to fight it. Maureen Langley, Post-Tribune, "Experts: Indiana's allergy season worse than usual this year," 3 July 2018 Still, her fellow Democrats jumped into the fray, helping Republicans to frame her remarks as harmful. Solomon Jones, Philly.com, "Maxine Waters deserves better from her party | Solomon Jones," 27 June 2018 Speakers blasted the court’s decision as harmful and urged people to vote in upcoming elections. Gary Warth, sandiegouniontribune.com, "Travel ban sparks downtown demonstration," 26 June 2018 The couple's company, Magnolia Homes, broke the provision that protects occupants from exposure to dangerous lead levels, which is particularly harmful to children and which many pre-1978 homes contain, as a result from home renovations. Taysha Murtaugh, Country Living, "Chip and Joanna Gaines Pay $40,000 EPA Fine for Lead Paint Violations," 6 June 2018 Given the long and sorry list of harmful and toxic chemicals in cigarettes, vaping is almost certainly less dangerous to your health. Scientific American, "E-Cigs and Second-Hand Vaping," 18 May 2018

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.

See More

First Known Use of harmful

14th century, in the meaning defined above

Keep scrolling for more

Learn More about harmful

Dictionary Entries near harmful

harm's way

harman

harmattan

harmful

harmless

Harmolita

harmonia

Statistics for harmful

Last Updated

16 Sep 2018

Look-up Popularity

Time Traveler for harmful

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

See more words from the same century

Keep scrolling for more

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 \

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

Keep scrolling for more

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

Comments on harmful

What made you want to look up harmful? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

a magnificent or impressive array

Get Word of the Day daily email!

Test Your Vocabulary

Name that Food Quiz

How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

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