noun
( -es )
Etymology: Middle English brightnesse, from Old English beorhtnes, byrhtnes, bryhtnes, from beorht, byrht, bryht bright + -nes -ness
1.
a. : the quality or state of being bright: as
(1) : brilliance , luster
(2) : splendor , fame
(3) : sharpness of wit : acuteness
b. : an instance of such a quality or state
2.
a. : the attribute of light-source colors by which the light source appears to emit light varying from a minimum for very dim to a maximum for very bright
b. : luminance