Hole where star is being pulled back (5)
I believe the answer is:
sinus
'hole' is the definition.
(I've seen this before)
'star is being pulled back' is the wordplay.
'star' becomes 'sun' (the Sun is a star).
'being pulled back' shows that the letters should be reversed in order.
'sun'+'is'='sunis'
'sunis' backwards is 'SINUS'.
'where' is the link.
(Other definitions for sinus that I've seen before include "chamber" , "Air cavity in the cranial bones" , "Channel between brain and skull" , "Bodily cavity" , "Anatomical cavity" .)