Bow at the finish, after a bad start (4)
I believe the answer is:
bend
'bow' is the definition.
(both can mean a curve)
'the finish after a bad start' is the wordplay.
'the finish' becomes 'end' (I've seen this in other clues).
'after' means one lot of letters go next to another.
'start' suggests taking the first letters.
The first letter of 'bad' is 'b'.
'end' after 'b' is 'BEND'.
'at' is the link.
(Other definitions for bend that I've seen before include "Repair" , "Dish of raw vegetables" , "Influence, bow" , "Corner" , "Lean forward" .)