Heavenly body giving half of us a shock (6)
I believe the answer is:
saturn
'heavenly body' is the definition.
(Saturn is an example)
'half of us a shock' is the wordplay.
'half of' means to take half the letters.
'shock' becomes 'turn' (I've seen this in other clues).
'us' cut in half is 's'.
's'+'a'+'turn'='SATURN'
'giving' is the link.
(Other definitions for saturn that I've seen before include "Sixth planet from the sun" , "orbits the sun" , "tried to pass vessel" , "The dark planet" , "Massive body ringed" .)