Pronunciation: (lOO"mu-nos'i-tē),[key] —n., —pl.-ties. 1. luminance (def. 2).
2. the quality of being intellectually brilliant, enlightened, inspired, etc.: The luminosity of his poetry is unequaled. 3. something luminous.
4. Astron.the brightness of a star in comparison with that of the sun: the luminosity of Sirius expressed as 23 indicates an intrinsic brightness 23 times as great as that of the sun.
5. Also called luminos'ity fac"tor.Optics.the brightness of a light source of a certain wavelength as it appears to the eye, measured as the ratio of luminous flux to radiant flux at that wavelength.