Illuminance
Part of speech: noun
Definition: The luminous flux incident on unit area of a surface; measured in lux or lumens
Illumination
Part of speech: noun
Definition: The act of illuminating, or supplying with light; the state of being illuminated.Festive decoration of houses or buildings with lights.Adornment of books and manuscripts with colored illustrations. See illuminate (transitive verb).
Example sentence: This is the great object held out by this association; and the means of attaining it is illumination, enlightening the understanding by the sun of reason which will dispell the clouds of superstition and of prejudice.