Source : Webster's Revised Unabridged Dictionary (1913)

Luminescence \Lu`mi*nes"cence\, n. [See {Luminescent}.]
   1. (Physics) Any emission of light not ascribable directly to
      incandescence, and therefore occurring at low
      temperatures, as in phosphorescence and fluorescence or
      other luminous radiation resulting from vital processes,
      chemical action, friction, solution, or the influence of
      light or of ultraviolet or cathode rays, etc.

   2. (Zo["o]l.)
      (a) The faculty or power of voluntarily producing light,
          as in the firefly and glowworm.
      (b) The light thus produced; luminosity; phosphorescence.

Source : WordNet®

luminescence
     n 1: light not due to incandescence; occurs at low temperatures
     2: light from nonthermal sources [syn: {glow}]