noun (n)

• the quality of being luminous; emitting or reflecting light

  kualitas yang bercahaya; memancarkan cahaya atau mencerminkan

  Example:
  Its luminosity is measured relative to that of our sun.
  

  Synonym:
  brightness, brightness level, light, luminance, luminousness
  

  source: wordnet30
• The quality or state of being luminous; luminousness.

  kualiti atau keadaan yang bercahaya; luminousness.

  source: webster1913