reclusive American author (8)
I believe the answer is:
salinger
(Other definitions for salinger that I've seen before include "Jerome D ........ wrote ` ` The Catcher in the Rye' '" , "J. D. ..., author of Catcher in the Rye" , "US novelist" , "'JD..., author of The Catcher in the Rye (8)'" , "US author of The Catcher in the Rye" .)