Antipathetic, unsympathetic and averse are often used as if they were synonyms. They are, however, not interchangeable if employed in accord with careful usage.
Strictly, antipathetic is applied to things or to persons objectively considered that are disagreeable, distasteful, uncongenial, abhorrent, or repellent.
- the whole place and everything about it was antipathetic to her
—Trollope - settlers to whom this formula was antipathetic were asked to go elsewhere
—Repplier - ushering in the year with a series of calls on the most remote and the most personally antipathetic of our innumerable relations
—Huxley
In broader use the word is applied to persons or groups of persons as though it were the antonym of sympathetic; it may imply animosity and not merely the absence of sympathy.
- he really disliked Sir Theodosius, who was in every way antipathetic to him
—Joseph Shearing
Unsympathetic, on the other hand, is with rare exceptions applied to persons or to things personified or thought of as expressing personal feeling and suggests an attitude of indifference or insensitiveness or the absence of a response to an appeal to one’s interest or emotions.
- an unsympathetic nurse
- an unsympathetic review of a new book
Averse (for synonyms in this sense see DISINCLINED) is closer to unsympathetic than to antipathetic in that it suggests the spirit in which a person meets something objective rather than the effect of a thing upon a person. However, averse implies not merely a lack of response but a definite turning away and consequently either avoidance or rejection.
- averse to a suggestion
- averse to exercise on a hot day
Thus, a man may be unsympathetic by nature yet not be averse to helping the poor. In general, it may be said that one is averse to (or, chiefly British, from) anything which is antipathetic to one.