brighten

Short definition from Wiktionary

Verb

1. 1
   To make bright or brighter in color.
2. 2
   To make illustrious, or more distinguished; to add luster or splendor to
3. 3
   To make more cheerful and pleasant; to enliven
4. 4
   To grow bright, or more bright in color; to clear up
5. 5
   To become brighter or more cheerful in mood