Which term defines the act of making a concept more understandable through demonstration?

The term that best describes the act of making a concept more understandable through demonstration is "illustrate." To illustrate something typically involves providing examples, visual aids, or explanations that clarify an idea or topic, making it easier for the audience to comprehend. This term encompasses the idea of enhancing understanding by presenting concrete instances or demonstrations.

While the other options convey important aspects of communication, they do not specifically capture the essence of using demonstrations to clarify concepts. "Refine" usually pertains to the process of improving or perfecting something, rather than explaining or demonstrating. "Convey" means to communicate or express an idea, but it does not explicitly suggest the use of illustrations or demonstrations for clarity. "Reveal" tends to imply uncovering or disclosing something that was hidden, which does not necessarily correlate with making a concept more understandable through demonstration. Therefore, "illustrate" is the most fitting term in this context.