If you want to describe a negative reaction to something (such as a harmful side effect from medication) or dangerous meteorological conditions (such as a snowstorm), adverse is the correct choice; you would not say that you had an averse reaction to medication or that there was averse weather.
ADVERSE meaning: 1. having a negative or harmful effect on something: 2. having a negative or harmful effect on…. Learn more.
Adverse decisions, conditions, or effects are unfavorable to you. The police said Mr. Hadfield's decision would have no adverse effect on the progress of the investigation.
Definition of adverse adjective in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.
It pertains more often to effects or events: adverse reviews; adverse conditions; adverse trends. Averse is used of people and means opposed or disinclined: We are not averse to staying in town another day.
Adverse is seldom used of people but rather of effects or events, and it usually conveys a sense of hostility or harmfulness: adverse reviews; adverse winds; adverse trends in the economy.
Adverse is sometimes confused with averse, though the meanings are somewhat different. Adverse most often refers to things, denoting something that is in opposition to someone's interests — something one might refer to as an adversity or adversary — (adverse winds; an attitude adverse to our ideals).
adverse, adj. & n. meanings, etymology, pronunciation and more in the Oxford English Dictionary
adverse, adj. & n. meanings, etymology and more | Oxford English Dictionary
If it's adverse, it's working against you — like adverse weather conditions or the adverse effects of eating too much sugar. Coming from the Latin adversus meaning "turned against," adverse is an adjective describing a factor that seems to work against or actively harm something.