Earnest request or petition (8)
I believe the answer is:
entreaty
I believe this is a double definition.
'earnest request' is the first definition.
(I've seen this in another clue)
'petition' is the second definition.
(both can mean a request)
(Other definitions for entreaty that I've seen before include "Supplication" , "Teeny rat (anag.)" , "application for assistance" , "Earnest plea" , "Appeal" .)