Synonyms of adverse in English:

adverse


See US English definition of adverse

See UK English definition of adverse

See Spanish definition of adverso

adjective

1‘the plane crashed into a lake in adverse weather conditions’

SYNONYMS
unfavourable, disadvantageous, inauspicious, unpropitious, unfortunate, unlucky, untimely, untoward
disagreeable, unpleasant, bad, poor, terrible, dreadful, dire, wretched, nasty, hostile
ANTONYMS

favourable

2‘the company knew of the drug's adverse side effects’

SYNONYMS
harmful, dangerous, injurious, detrimental, hurtful, deleterious, destructive, pernicious, disadvantageous, unfavourable, unfortunate, unhealthy
ANTONYMS

beneficial

3‘the military feared an adverse response from the American public’

SYNONYMS
hostile, unfavourable, antagonistic, unfriendly, ill-disposed, negative, opposing, opposed, contrary, dissenting, inimical, antipathetic, at odds
ANTONYMS

positive, friendly