antipathic

This term describes a visceral, instinctive repulsion that goes beyond simple disagreement or dislike. It suggests an inherent incompatibility or a deep-seated emotional aversion that often manifests as an immediate, negative reaction upon encounter.

In modern usage, "antipathic" is rare and carries a highly formal or academic register. It is frequently superseded by "antipathetic," though "antipathic" specifically emphasizes the state of feeling the antipathy rather than the active expression of it.