Waste grounds (5)
I believe the answer is:
dregs
This clue is a double definition.
'waste' is the first definition.
(thesaurus)
'grounds' is the second definition.
(synonyms)
(Other definitions for dregs that I've seen before include "Wine sediment" , "Remnant of drink" , "Remaining sediment" , "Leftover drink, sediment" , "Sediment, lees" .)