Adverse and Averse are often confused because they sound similar and only have one alphabet differentiating them from each other –'d' in adverse; 'v' in averse. Both words, though, have different meanings and each is used in different contexts.
Adverse is an adjective.
Meanings: unfavourable; unpleasant; bad; difficult; opposing; contrary; hostile
Averse is an adjective.
Meanings: reluctant; disinclined; loath; indisposed; unenthusiastic.
Examples of Adverse:
1. The doctor explained to the patient the adverse effects of smoking and drinking.
2. The crowd was making adverse reactions to the politician's speech.
3. Removing forest areas and introducing commercial structures would adversely affect the environment.
Examples of Averse:
1. The film producer was averse to releasing the movie just before the State Board exams as it would affect ticket sales.
2. The student was averse to reading his essay in front of the whole class.
3. Mahendra was averse to going on the trekking trip with his friends without a proper guide who knew the trails.