'Luminosity' definitions:

Definition of 'luminosity'

From: WordNet
noun
The quality of being luminous; emitting or reflecting light; "its luminosity is measured relative to that of our sun" [syn: luminosity, brightness, brightness level, luminance, luminousness, light]

Definition of 'Luminosity'

From: GCIDE
  • Luminosity \Lu`mi*nos"i*ty\, n. The quality or state of being luminous; luminousness. [1913 Webster]