Stage favourite's comeback (4)
I believe the answer is:
step
'stage' is the definition.
(as in a step or stage of a process)
'favourite's comeback' is the wordplay.
'favourite's' becomes 'pet's' ('pet' can be a synonym of 'favourite').
'comeback' shows that the letters should be reversed in order.
'pets' backwards is 'STEP'.
(Other definitions for step that I've seen before include "Movement in dancing" , "one stage of flight" , "Single pace" , "Indian garment" , "Pace; foothold" .)