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

These invisible fragments may be toxic on their own, and they also have the potential to harbor a layer of harmful microbes or chemicals.

From Popular-Science

That said, scientists haven’t fully nailed down how harmful subway particles may be to human health.

From Popular-Science

It’s not harmful in small amounts, but higher concentrations become dangerous.

From Popular-Science

The work of organizers over the past eight months continues a long tradition of confronting unnecessary and harmful investments in institutions like the police.

From Washington Post

It’s also a place where people spread harmful misinformation—a problem that has proliferated on the platforms of its more mature rivals.

From Fortune

Not long ago, the concept of diversity was viewed as anti-meritocratic—even harmful.

From The Daily Beast

Others fear that giving them the force of regulation could be more harmful because they would become outdated quickly.

From The Daily Beast

So why are we continually inundated with images and hate speech perpetuating this harmful lie?

From The Daily Beast

It will likely be harmful to the reputations of both the president and vice president.

From The Daily Beast

Another act, however, may be considered immoral not because it is harmful but because it evinces disloyalty.

From The Daily Beast

This line is not in the F. text; it seems to mean—'a wave, harmful in wearing away the shore.'

From Project Gutenberg

There is one great point in our favour, these people can do nothing very harmful so long as those papers are missing.

From Project Gutenberg

In addition, this advertising may be harmful to those juveniles and adolescents with whom this Committee is primarily concerned.

From Project Gutenberg

It involves a continual struggle against harmful influences from outside.

From Project Gutenberg

Tell me,” said Hadria, “what are the qualities in a human being that make him most serviceable, or least harmful?

From Project Gutenberg

Related Words

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