Light region in shade there allowed (8)
I believe the answer is:
ethereal
'light' is the definition.
(I've seen this in another clue)
'region in shade there allowed' is the wordplay.
'region in' indicates the answer is hidden within the clue.
'ETHEREAL' is hidden within 'shade there allowed'.
(Other definitions for ethereal that I've seen before include "Like fairies" , "gossamer" , "Ultra-refined" , "exquisitely airy" , "Insubstantial or not of this world" .)