"Zuckerman Unbound" author (4)
I believe the answer is:
roth
'zuckerman unbound author' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for roth that I've seen before include "American Jewish novelist, Philip, b. 1933" , "Portnoy's Complaint author, d. 2018" , "Philip --, US author" , "Author of Portnoy's Complaint, b. 1933" , "American writer" .)