antipathy (n.)
c. 1600, "natural aversion, hostile feeling toward," from Latin antipathia, from Greek antipatheia, abstract noun from antipathes "opposed in feeling, having opposite feeling; in return for suffering;" also "felt mutually," from anti "opposite, against" (see anti-) + pathein "to suffer, feel" (from PIE root *kwent(h)- "to suffer").

An abuse has crept in upon the employment of the word Antipathy. ... Strictly it does not mean hate,—not the feelings of one man set against the person of another,—but that, in two natures, there is an opposition of feeling. With respect to the same object they feel oppositely. [Janus, or The Edinburgh Literary Almanack, 1826]

If you look at the Greek roots of this word — anti- ("against") and pathos ("feeling") — you can see that antipathy is a feeling against someone or something. In general, antipathies are feelings that are kept at least somewhat under wraps and are not out in the open.