Author’s hoax involving gun lobbyists (6)
I believe the answer is:
conrad
'author's' is the definition.
(Joseph Conrad)
'hoax involving gun lobbyists' is the wordplay.
'hoax' becomes 'cod' (cod can mean false or hoax).
'involving' indicates putting letters inside.
'gun lobbyists' becomes 'NRA' (National Rifle Association in the USA).
'cod' enclosing 'nra' is 'CONRAD'.
(Other definitions for conrad that I've seen before include "Heart of Darkness author" , "Joseph --, author" , "Joseph ---, Polish-born novelist" , "Joseph --, writer (Lord Jim)" , "Joseph ...... wrote 'Lord Jim'" .)