Heavenly headwear (4)
I believe the answer is:
halo
'heavenly headwear' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for halo that I've seen before include "Aura round admired person" , "Band of light" , "Glittering aura" , "Saintly ring" , "Glowing ring (around saint's head)" .)