Want you coming back as a servant (6)
I believe the answer is:
lackey
'a servant' is the definition.
(lackey is a kind of servant)
'want you coming back' is the wordplay.
'want' becomes 'lack' ('lack' can be a synonym of 'want').
'you' becomes 'ye'.
'coming back' shows that the letters should be reversed in order.
'ye' in reverse letter order is 'ey'.
'lack'+'ey'='LACKEY'
'as' acts as a link.
(Other definitions for lackey that I've seen before include "An archaic servant or underling" , "Minion or servile follower" , "An archaic menial or follower" , "assistant" , "Liveried servant" .)