What term describes the direct, immediate, and exclusive authority a person has over a thing?

The term that describes the direct, immediate, and exclusive authority a person has over a thing is ownership. Ownership entails not only having control over the property but also the right to use, manage, and dispose of it as the owner sees fit. This concept is fundamental in property law, as ownership signifies a complete bundle of rights, which includes possession, and the authority to exclude others from the property.

While possession refers to the physical control of a property, it does not always imply legal ownership. Leasing involves granting someone the right to use property in exchange for rent, which clearly denotes that ownership remains with the lessor. Usufruct is a legal right that allows a person to use and enjoy the benefits of someone else's property without possessing it, which also distinguishes it from true ownership.

Thus, ownership is the most accurate term in this context, capturing the essence of exclusive authority and control over a particular thing.