/looh"meuh neuhns/, n.
1. the state or quality of being luminous.
2. Also called luminosity. the quality or condition of radiating or reflecting light: the blinding luminance of the sun.
3. Optics. the quantitative measure of brightness of a light source or an illuminated surface, equal to luminous flux per unit solid angle emitted per unit projected area of the source or surface.
[1875-80; < L lumin- (s. of lumen) light + -ANCE]

* * *

Universalium. 2010.