The bit to abandon (5)
I believe the answer is:
scrap
I believe this clue is a double definition.
'the bit' is the first definition.
('scrap' can be a synonym of 'bit')
'abandon' is the second definition.
(I've seen this before)
'to' is the link.
(Other definitions for scrap that I've seen before include "boxing match?" , "Discard the small fragment" , "Fragment or slang fight (5)" , "argument" , "Cancel; fight" .)