Use the adjective interpretive to describe things that explain or define, like an interpretive dance that uses movements and gestures to convey the meaning of a piece of music.
Interpretive comes from the Latin word interpretari, which means "explain, expound, understand." Inter- means "between" or "among," so you know there will be two or more parts to things that are interpretive. It's a subjective response that involves the thing that's being interpreted and the person doing the interpreting. A reader might have an interpretive response to a book, a guide will give an interpretative description of a painting for a tour group, and so on.