Something is illuminated when the light shines on it. Literally or figuratively. A comment illuminates a concept; a door opening shines a light onto a new pathway; a light shines on an object and gives it definition.
Part of discernment is noticing what is being illuminated. For some of us, only the really obvious stuff sticks out, while others are better at clueing in to the subtleties.
I think I like it best when things slowly come into focus. For one thing, it's fun to imagine what's at the dark edges, just out of sight. It's fun to try to figure out what it is one is looking at, and to see it slowly come into view with the aid of more and more illumination. This gives one time to adjust, and readjust and ease into an idea without having to take a definite stand and then risk changing it. This is true for ideas, relationships, and objects. Things unfold, they come into view, they may even change shape, and the eyes (both the physical ones and the emotional and faithful ones) adjust and the brain engages. Plus there is the added bonus of laughing when one realizes how wrong the initial thought was. (A crocodile? No, wait, a toothbrush? Ah, the cat's tail.)
As I continue to discern my path these days, I pray for gentle, unfolding illumination amid the noisy and sudden brightness that makes up much of the rest of my world. So that I can take it in slowly rather than react suddenly. Discernment seems to be a word that means "things slowing coming into view, slowly illuminated to show the eyes of faith where the path ahead lies."