The bit after Ed's taken back leave (6)
I believe the answer is:
depart
'leave' is the definition.
(synonyms)
'the bit after ed's taken back' is the wordplay.
'the bit' becomes 'part' (both can mean a piece of something).
'after' means one lot of letters go next to another.
'taken back' shows that the letters should be reversed in order.
'ed' reversed gives 'de'.
'part' put after 'de' is 'DEPART'.
(Other definitions for depart that I've seen before include "Quit" , "Retire from" , "Take one's leave, go" , "Start out" , "Go away or leave" .)