Which term refers to a person's natural inclination or established habit?

The term that best describes a person's natural inclination or established habit is "bent." This word indicates a tendency or disposition towards a particular way of thinking, feeling, or behaving, often suggesting an innate or ingrained characteristic. It implies a more instinctive or automatic inclination rather than something that has been consciously chosen or adopted.

In contrast, "trait" refers to a distinguishing quality or characteristic, which can encompass a wide range of attributes, both inherited and developed, rather than specifically denoting a habitual action. "Behavior" refers to the actions or reactions of a person in response to external or internal stimuli, and while it may reflect habits, it does not inherently capture the notion of inclination. "Preference" signifies a choice or liking for one thing over another and relates more to individual selections rather than inherent tendencies or habits. Thus, "bent" is the term that accurately embodies the idea of a natural inclination or established habit.