Illuminate (5)
'illuminate' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for brighten that I've seen before include "Provide illuminations" , "Cheer up; clear up" , "Liven up" , "Illuminate, cheer up" , "Polish" .)
'illuminate' is the definition.
(I know that illuminate can be written as light)
This is all the clue.
(Other definitions for light that I've seen before include "Unimportant" , "Moored vessel warning sailors of a hazard" , "Eminent person" , "Pale" , "Not having full load" .)