Choose the one-word term for an individual who pursues an art or subject for personal enjoyment rather than as a trained or paid occupation.

The correct answer is Dilettante.

Step-by-Step Explanation:
A dilettante is an individual who engages in an art, science, or field of study purely for personal delight or amusement rather than as a formal, trained, or paid occupation. The term comes from the Italian verb dilettare, which means "to delight."

Analysis of Options:
1. Professional: Describes a person who engages in a specified activity as their main paid occupation rather than as a hobby.
2. Dilettante: Describes an amateur who pursues a subject for personal enjoyment without pursuing it as a full-time, trained, or paid career.
3. Authority: Refers to an established expert with comprehensive knowledge and command of a field.
4. Apprentice: Refers to a novice who is systematically learning a trade or skill from a master, usually aiming for professional qualification.

Therefore, the term that precisely fits the definition given in the question is Dilettante.