Fictional sleeper (3)
I believe the answer is:
rip
'fictional sleeper' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rip that I've seen before include "Epitaph" , "Severely criticise" , "Letters usually seen on gravestone" , "Letters often seen on gravestones" , "Letters for the deceased" .)