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

Derived Forms

• ˈharmfully, adverb
• ˈharmfulness, noun

Other Words From

• harmful·ly adverb
• harmful·ness noun
• quasi-harmful adjective
• quasi-harmful·ly adverb
• un·harmful adjective
• un·harmful·ly adverb

Word History and Origins

Origin of harmful¹

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

Example Sentences

The new study is the first to show that targeting specific forms of SUMOylation could prevent the harmful influx of immune cells that can trigger gut inflammation.

From Science Daily

“The isolation and mutual dependency…provided a culture within which unusual and harmful behaviours could develop,” the judge wrote.

From BBC

High cis fat diet mice, on the other hand, experienced shorter-term, less harmful effects like weight gain.

From Science Daily

It can lead to lung injury, coma and death within seconds when consumed in large amounts, but even small doses can still be very harmful.

From BBC

It should also be assessed how frightening, worrisome or harmful they are considered to be.

From Science Daily

Related Words

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