Push away social outcast making comeback (5)
I believe the answer is:
repel
'push away' is the definition.
(I've seen this in another clue)
'social outcast making comeback' is the wordplay.
'social outcast' becomes 'leper' (someone with leprosy).
'making comeback' is a reversal indicator.
'leper' written backwards gives 'REPEL'.
(Other definitions for repel that I've seen before include "Reject" , "See off" , "Beat back; cause disgust to" , "Drive or force back" , "Drive back or away" .)