Novel appears heartlessly mean about journalist (12)
I believe the answer is:
newspaperman
'journalist' is the definition.
(newspaperman is a kind of journalist)
'novel appears heartlessly mean about' is the wordplay.
'novel' becomes 'new' (similar in meaning).
'heartlessly' says to hollow out the word (remove centre letters).
'about' is an anagram indicator.
'mean' with its middle taken out is 'mn'.
'appears'+'mn'='appearsmn'
'appearsmn' is an anagram of 'spaperman'.
'new'+'spaperman'='NEWSPAPERMAN'
(Other definitions for newspaperman that I've seen before include "Journalist" , "One of our staff" , "One with editing skill" .)