Quick writer, Jonathan (5)
I believe the answer is:
swift
This clue is a double definition.
'quick' is the first definition.
(thesaurus)
'writer jonathan' is the second definition.
(Jonathan Swift)
(Other definitions for swift that I've seen before include "Anglo-Irish satirist" , "Jonathan ..., clergyman and satirist" , "Speedy - bird like a swallow" , "Happening quickly; author" , "Hasty" .)