Fights waste (6)
I believe the answer is:
scraps
I believe this clue is a double definition.
'fights' is the first definition.
(I know this)
'waste' is the second definition.
(I know that scraps is a type of waste)
(Other definitions for scraps that I've seen before include "Bits and pieces, or slang fights" , "Quarrels" , "Small fragments" , "bits left over?" , "Slangy fights for leftovers" .)