Truman —, author of 1958 novella Breakfast at Tiffany's (6)
I believe the answer is:
capote
(Other definitions for capote that I've seen before include "American author" , "Breakfast at Tiffany's writer" , "Persons" , "Author of Breakfast at Tiffany's, d. 1984" , "Truman - - , novelist" .)