Heavenly 'belt' (6)
I believe the answer is:
zodiac
'heavenly belt' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for zodiac that I've seen before include "It's divided into 12 constellations" , "Belt of twelve signs" , "Astrological band of the sky with 12 signs" , "Heavenly area" , "Heavenly region" .)