What would be the appropriate term for having strong opposition or repulsion towards something?

The appropriate term for having strong opposition or repulsion towards something is "aversion." This word specifically describes a strong feeling of dislike or avoidance, suggesting an active resistance to a particular subject, situation, or idea. For example, someone may have an aversion to certain foods, indicating they not only dislike them but also may go out of their way to avoid them.

In contrast, apathy denotes a lack of interest or concern; it doesn't convey strong opposition. Regret refers to a feeling of sadness or disappointment over something that has happened or been done, and indifference signifies a lack of interest, enthusiasm, or concern. Neither of these terms captures the essence of strong opposition or a feeling of repulsion in the way "aversion" does. Thus, "aversion" accurately represents the concept of strong opposition or repulsion.