Definition of adverse in US English:

adverse

adjective

  • Preventing success or development; harmful; unfavorable.

    ‘taxes are having an adverse effect on production’
    ‘adverse weather conditions’
    • ‘So when lawn edges become overgrown and tatty, it can have an adverse effect on the look of the whole garden.’
    • ‘Perhaps they never learned how to drive in adverse conditions in the first place.’
    • ‘The adverse publicity has caused tourists to stay away in droves from the countryside and towns.’
    • ‘Not only did they put up a good show in adverse circumstances, they entertained the crowd greatly.’
    • ‘The adverse publicity generated by the hijacking was the last thing the airline needed.’
    • ‘Despite the adverse blustery weather conditions, it was clear that Oxford had the edge.’
    • ‘Bacteria present in organic matter can have adverse effects on human and animal health.’
    • ‘The most common adverse effects reported related to skin irritation and skin burning.’
    • ‘Roadworks on three of the routes in and out of Skipton are having an adverse effect on local businesses.’
    • ‘I hope his commitment and long hours do not have adverse effects on him or his family.’
    • ‘The child required urgent medical attention but did not develop long term adverse effects.’
    • ‘A hike in interest rates could have an adverse effect on house prices and in terms of consumer wealth.’
    • ‘Fortunately, most schools forced to close due to the adverse weather were due to reopen today.’
    • ‘She said the development would have major adverse impacts on the beauty of the landscape.’
    • ‘Of course, there is also the adverse publicity that could dog them for years to come.’
    • ‘The development will not have any adverse effect upon bats or other wildlife living in the area.’
    • ‘He believed it would have adverse effect on business and trade in the community.’
    • ‘It was bound to attract adverse publicity and bring the profession into disrepute.’
    • ‘Sources say that clients are leaving in droves because of the continuing adverse publicity.’
    • ‘The trials had been cancelled after the drug was found to cause an adverse reaction.’
    unfavourable, disadvantageous, inauspicious, unpropitious, unfortunate, unlucky, untimely, untoward
    harmful, dangerous, injurious, detrimental, hurtful, deleterious, destructive, pernicious, disadvantageous, unfavourable, unfortunate, unhealthy
    hostile, unfavourable, antagonistic, unfriendly, ill-disposed, negative, opposing, opposed, contrary, dissenting, inimical, antipathetic, at odds
    View synonyms

Usage

Adverse means ‘hostile, unfavorable, opposed,’ and is usually applied to situations, conditions, or events—not to people: the dry weather has had an adverse effect on the garden. Averse is related in origin and also has the sense of ‘opposed,’ but is usually employed to describe a person's attitude: I would not be averse to making the repairs myself. See also averse

Origin

Late Middle English: from Old French advers, from Latin adversus ‘against, opposite’, past participle of advertere, from ad- ‘to’ + vertere ‘to turn’. Compare with averse.

Pronunciation