Drop argument (5)
I believe the answer is:
scrap
I believe this clue is a double definition.
'drop' is the first definition.
(I've seen this before)
'argument' is the second definition.
(I've seen this in another clue)
(Other definitions for scrap that I've seen before include "Scuffle" , "Leftover; fight" , "Waste metal or slang fight" , "Dispense with - waste material" , "rubbish" .)