38 adverse synonyms include unfavourable, disadvantageous, inauspicious, unpropitious, unfortunate, unlucky, untimely, untoward, and unpleasant. Adverse is an adjective, and its antonyms are favorable, beneficial, positive, and friendly. Here are some additional synonyms for "adverse" with example sentences.
38 other ways to say adverse.
He faced adverse weather conditions yesterday.
The medication caused adverse side effects.