Other forms: illuminatingly
Something that's illuminating makes you better informed, more aware, or more inspired. An illuminating documentary film gives you all kinds of new information about its subject.
Describe things as illuminating when they clarify the situation or explain the facts. A long conversation with someone you don't know well can be illuminating, helping you understand her much better. Likewise, studying the details of any subject, whether it's dog training or art history, is also illuminating. The verb illuminate means "light up," and it comes from the Latin word illuminare, "to throw into light or make bright," which is also figuratively used to mean "illustrate."