Bit in fight (5)
I believe the answer is:
scrap
I believe this is a double definition.
'bit' is the first definition.
(I know that bit can be written as scrap)
'fight' is the second definition.
(a scrap is a minor fight)
'in' is the link.
(Other definitions for scrap that I've seen before include "bundle" , "Small piece - fight" , "Small (leftover) piece" , "Small fight about a smal fragment" , "boxing match?" .)