* Aversion: A strong dislike or disinclination.
* Reluctance: Unwillingness to do something.
* Disinclination: A lack of willingness or enthusiasm.
* Resistance: The act of opposing something.
* Inability: Lack of the power or skill to do something.
* Avoidance: The act of staying away from something.
Example:
* Propensity: He has a propensity for gambling.
* Antonym (Aversion): He has a strong aversion to gambling.
The best antonym will depend on the specific nuance you're trying to convey.