Universal remedy (4-3)
(Other definitions for cure-all that I've seen before include "Panacea, nostrum" , "Universal panacea" , "Universal remedy" .)
'universal remedy' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for panacea that I've seen before include "Universal medicine" , "Cure-all in a canape" , "that can make anything better" , "wonder drug" , "that's going to help a lot" .)