Heartfelt appeal (4)
I believe the answer is:
plea
'heartfelt appeal' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for plea that I've seen before include "Statement in court" , "Lightly char" , "Answer made by the accused to the charge" , "Petition or supplication" , "Defendant's answer to a charge or claim" .)