/ ˈædvɜːs; ədˈvɜːs; NAmE -vɜːrs/ adjective
[ usually before noun ] negative and unpleasant; not likely to produce a good result :
adverse change / circumstances / weather conditions
Lack of money will have an adverse effect on our research programme.
They have attracted strong adverse criticism.
This drug is known to have adverse side effects.
► ad·verse·ly adverb :
Her health was adversely affected by the climate.
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WORD 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 .