adverse
The medication may cause adverse side effects.
The medication might produce harmful reactions.
Preventing success or development; harmful or unfavorable.
They faced adverse weather conditions during the expedition.
The harsh weather made the expedition difficult.
Adverse reactions to the vaccine are rare.
Negative responses to the vaccine are uncommon.
Often used in medical, legal, or technical contexts to describe negative effects or conditions.
Acting in a contrary direction; opposing.
The judge ruled against the adverse party.
The judge decided in favor of the opposing side.
Common in legal terminology to describe opposing interests or parties.
Collocations
Pro Tip
Avoid confusion with 'averse'
'Adverse' refers to things (conditions, effects), while 'averse' describes feelings (e.g., 'She is averse to risk').
Gold Rule
Use 'adverse' for conditions or effects
Example: 'adverse weather' (not 'averse weather').
Word Origin
From Latin *adversus* (turned against), past participle of *advertere* (to turn toward), from *ad-* (to) + *vertere* (to turn).
Usage Notes
Avoid confusing 'adverse' with 'averse' (reluctant or opposed to something). 'Adverse' describes conditions or effects, while 'averse' describes feelings or attitudes.