Bit for king or knight? (5)
I believe the answer is:
piece
This clue is a double definition.
'bit' is the first definition.
(I know that bit can be written as piece)
'king or knight?' is the second definition.
(I've seen this in another clue)
'for' acts as a link.
(Other definitions for piece that I've seen before include "Musical composition" , "one of eight once ready for the Spanish?" , "King, perhaps" , "Separate part of a whole" , "rook, perhaps" .)