Novelist Hemingway (6)
I believe the answer is:
'novelist hemingway' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ernest that I've seen before include "chap" , "American writer . . . . . . Hemingway" , "fellow" , "The boy sounds serious" , "Resent (anag) - man" .)