Adjective harmful has 6 senses
- noxious, harmful - injurious to physical or mental health; "noxious chemical wastes"; "noxious ideas"
- harmful - able or likely to do harm
Antonym: safe (indirect, via dangerous)
- harmful - causing or capable of causing harm; "too much sun is harmful to the skin"; "harmful effects of smoking"
Antonyms: harmless, innocent, innocuous, inoffensive, unoffending
- disadvantageous, harmful - constituting a disadvantage
- adverse, harmful, inauspicious, untoward - contrary to your interests or welfare; "adverse circumstances"; "made a place for themselves under the most untoward conditions"
Antonyms: favorable, favourable (indirect, via unfavorable)
- evil, harmful, injurious - tending to cause great harm
Antonyms: benign, benignant (indirect, via malign)
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