Just light entertainment (4)
I believe the answer is:
fair
This clue is a triple definition!
'just' is the first definition.
('fair' is associated in meaning with 'just')
'light' is the second definition.
(thesaurus)
'entertainment' is the third definition.
(fair is a kind of entertainment)
(Other definitions for fair that I've seen before include "Considerable" , "'Just, meet (4)'" , "Beautiful like maiden of old" , "Sign following Pisces" , "Light coloured" .)