Bright'ness, n.
n. [A-S. beorhtnes. See BRIGHT.]
Sense 1. The quality of being bright; splendor; luster; brilliancy.
A sudden brightness in his face appeared. Crabbe.
Sense 2. Acuteness, applied to the faculties; sharpness of wit. “The brightness of his parts . . . distinguished him.” Prior.
Synonyms—Splendor; luster; radiance; resplendence; brilliancy; effulgence; glory; clearness; transparency.