illumination [ɪˌluːmɪˈneɪʃən] n 1. the act of illuminating or the state of being illuminated 2. a source of light 3. (often plural) Chiefly Brit a light or lights, esp coloured lights, used as decoration in streets, parks, etc. 4. spiritual or intellectual enlightenment; insight or understanding 5. the act of making understood; clarification 6. (Communication Arts / Printing, Lithography & Bookbinding) decoration in colours, gold, or silver used on some manuscripts or printed works 7. (Physics / General Physics) Physics another name (not in technical usage) for illuminance illuminational adj Collins English Dictionary – Complete