Adequate light (4)
I believe the answer is:
fair
I believe this is a double definition.
'adequate' is the first definition.
('fair' can be a synonym of 'adequate')
'light' is the second definition.
(thesaurus)
(Other definitions for fair that I've seen before include "not cloudy" , "the place for a roundabout" , "Equitable ? - trade show" , "Just - swings and roundabouts" , "light headed" .)