harmful

[hahrm-fuhl]

adjective

1. causing or capable of causing harm; injurious.

   a harmful idea;

   a harmful habit.

   Synonyms: deleterious, damaging, detrimental, hurtful
   Antonyms: beneficial

harmful

/ ˈhɑːmfʊl /

adjective

1. causing or tending to cause harm; injurious

Other Word Forms

• harmfully adverb
• harmfulness noun
• quasi-harmful adjective
• quasi-harmfully adverb
• unharmful adjective
• unharmfully adverb

Word History and Origins

Origin of harmful¹

First recorded before 1000; Middle English; Old English hearmful; harm, -ful

Example Sentences

The next steps are to find a way to neutralize the harmful protein and test if this can reduce VT burden and infarct size.

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The pharmacists' watchdog has promised to investigate and "take action" after the BBC exposed illegal and potentially harmful practices in the aesthetic Botox industry.

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All England players, including age-grade squads, are trained in being "active bystanders" to intervene and protect others from harmful behaviour.

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But this discovery, the scientists say, could be used to help manage harmful levels of stress.

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It said there are "serious constraints" on the next four biggest taxes - corporation tax, council tax, business rates and fuel duties - while "some other tax-raising options would be especially economically harmful".

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Related Words

• adverse 
• bad 
• catastrophic 
• damaging 
• destructive 
• detrimental 
• disadvantageous 
• disastrous 
• inimical 
• noxious 
• painful 
• pernicious 
• risky 
• ruinous 
• sinful 
• toxic 
• unhealthy 
• unsafe