Illumination

Main Entry: il·lu·mi·na·tion 

Pronunciation: \i-ˌlü-mə-ˈnā-shən\

Function: noun

Date: 14th century

1 : the action of illuminating or state of being illuminated: as a :spiritual or intellectual enlightenment b (1) : a lighting up (2) :decorative lighting or lighting effects c : decoration by the art of illuminating 2 : the luminous flux per unit area on an intercepting surface at any given point3 : one of the decorative features used in the art of illuminating or in decorative lighting

Source: http://www.merriam-webster.com/dictionary/illumination

Etymology of illumination
mid-14c., "spiritual enlightenment," from O.Fr. illumination, from L.illuminationem (nom. illuminatio), from illuminare "to throw into light," from in- "in" (with assimilation of -n- to the following consonant) + lumen (gen. luminis) "light." Meaning "the action of lighting" is from 1560s.
Source: http://www.etymonline.com/