Minister after revolution has little time for scum (6)
I believe the answer is:
vermin
'scum' is the definition.
(thesaurus)
'minister after revolution has little time' is the wordplay.
'minister' becomes 'rev' (short for reverend).
'after revolution' says the letters should be written backwards.
'has' means one lot of letters go next to another.
'little time' becomes 'min' (short for minute).
'rev' backwards is 'ver'.
'ver'+'min'='VERMIN'
'for' is the link.
(Other definitions for vermin that I've seen before include "cockroaches, for example" , "Annoying small animals or insects" , "Pests, rats say" , "E.g. unpleasant rodents" , "Small pests" .)