Adverse - averse
From Hull AWE
Don't confuse these two words. If you do, spellcheckers will let you get away with it. Their meanings are not very far apart, but should not be confused.
- adverse means, roughly, 'contrary', 'against' or 'unfavourable'. If you have adverse wind, it is blowing in your face; adverse fortune is bad luck; and adverse effects are those you don't want. Adverse is an adjective used to describe external things like weather or chance or results.
- averse on the other hand is used to describe an internal state of mind. "I am averse to your going," says the jealous father; "The politician found himself averse to telling the truth about his relationship in public." It means 'opposed [to]', 'disinclined', 'disliking', 'against'. It is often found in the construction (a litotes) "I am not averse to [e.g. another drink]."
- You may also like to see AWE's advice on adversary.