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Definitions

harmful

[hahrm-fuhl] / ˈhɑrm fəl /
ADJECTIVE
injurious, hurtful
Synonyms
STRONGEST
adverse bad catastrophic damaging destructive detrimental disadvantageous disastrous inimical noxious painful pernicious risky ruinous sinful toxic unhealthy unsafe
WEAK
baleful baneful calamitous cataclysmic consumptive corroding corrupting crippling deleterious dire evil harassing incendiary internecine malefic malicious malignant menacing mischievous murderous nocuous pestiferous pestilential sinister subversive undermining unwholesome virulent
Antonyms
STRONGEST
advantageous aiding assisting beneficial favorable fortunate good harmless healthy helpful honest kind lucky profitable safe upright

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Public figures hold significant influence, and when that influence is used to spread harmful rhetoric, it can contribute to a broader culture of intolerance.

From The Wall Street Journal • Apr. 21, 2026

Tilstone said this could be taken advantage of by certain species which were harmful to humans, fish and shellfish.

From BBC • Apr. 15, 2026

“In some instances, stopping your medicine may be more harmful to your health than continuing to take the recalled medicine,” the FDA said.

From Los Angeles Times • Apr. 15, 2026

The study revisits existing data while setting aside a common assumption that humans are inherently harmful to natural systems.

From Science Daily • Apr. 14, 2026

Many of the chemical agents in this alarming melange imitate and augment the harmful effects of radiation, and within the groups of chemicals themselves there are sinister and little-understood interactions, transformations, and summations of effect.

From "Silent Spring" by Rachel Carson

Vocabulary lists containing harmful

Earth Day

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Unfavorable

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