n.1. a. The act of illuminating.
b. The state of being illuminated.
2. A source of light.
3. Decorative lighting.
4. Spiritual or intellectual enlightenment.
5. Clarification; elucidation.
6. a. The art or act of decorating a text, page, or initial letter with ornamental designs, images, or lettering.
b. An example of this art.
7. Physics The luminous flux per unit area at any point on a surface exposed to incident light. Also called illuminance.