Adverse and Averse are in origin and in common use contrasted rather than synonymous terms, though they are occasionally used as though similar in meaning.
Adverse implies opposition that interferes and it is applied to the thing that stands in the way of one’s progress or success.
- the leader would tolerate no adverse opinions among his followers
Averse implies repugnance in the person opposed to a thing rather than a quality in the thing which is opposed.
- the leader is averse to all independence of opinion among his followers
However they are sometimes used as synonyms with only this distinction, that adverse is chiefly referred to opinion or intention and averse to feeling and inclination.
- I . . . hope that our periodical judges will not be very adverse to me, and that perhaps they may even favor me
—Cow per - the writer of critical studies . . . has to mediate between the author whom he loves and the public, who are certainly indifferent and frequently averse
—Stevenson - what cat’s averse to fish
—Gray