Synonyms of harmful in English:

harmful


See US English definition of harmful

See UK English definition of harmful

See Spanish definition of nocivo

adjective

1‘the harmful effects of cigarette smoking’

SYNONYMS
damaging, injurious, detrimental, dangerous, deleterious, unfavourable, negative, disadvantageous, unhealthy, unwholesome, hurtful, baleful, wounding, destructive, environmentally unfriendly
noxious, hazardous, poisonous, toxic, deadly, lethal
bad, evil, malign, malignant, malevolent, corrupting, subversive, pernicious
rare baneful, maleficent, malefic
ANTONYMS

beneficial, harmless