Patience, perhaps, Delaware police partly used up (5)
I believe the answer is:
opera
'patience perhaps' is the definition.
'delaware police partly used up' is the wordplay.
'partly used' indicates the answer is hidden within the clue (part of the clue is used to make the answer).
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'arepo' is hidden within 'delaware police'.
'arepo' back-to-front is 'OPERA'.
(Other definitions for opera that I've seen before include "eg Otello" , "Musical works" , "One with soap perhaps" , "Throw a rope for the musical" , ""The Magic Flute", for example" .)