Bright students turning away from books (6)
I believe the answer is:
sunlit
'bright' is the definition.
(similar in meaning)
'students turning away from books' is the wordplay.
'students' becomes 'nus' (I've seen this before).
'turning away' says the letters should be written backwards.
'from' is a charade indicator (letters next to each other).
'books' becomes 'lit' (abbreviation for literature).
'nus' back-to-front is 'sun'.
'sun'+'lit'='SUNLIT'
(Other definitions for sunlit that I've seen before include "In full daylight" , "Provided with illumination, naturally" , "Bright with solar illumination" , "Illuminated by daylight" , "Hit by solar rays" .)