A star looking embarrassed on the way back is in pieces (7)
I believe the answer is:
asunder
'in pieces' is the definition.
(I've seen this before)
'a star looking embarrassed on the way back' is the wordplay.
'star' becomes 'sun' (Sun is an example).
'looking embarrassed' becomes 'red' (I've seen this before).
'on the way back' says the letters should be written in reverse.
'red' backwards is 'der'.
'a'+'sun'+'der'='ASUNDER'
'is' is the link.
(Other definitions for asunder that I've seen before include "Apart (archaic)" , "(Split) apart" , "Sad rune (anag.)" , "(Split) into pieces" , "(Torn) into parts" .)