Earnestly, genuinely (9)
I believe the answer is:
sincerely
This clue is a double definition.
'earnestly' is the first definition.
(thesaurus)
'genuinely' is the second definition.
(I've seen this before)
(Other definitions for sincerely that I've seen before include "without hypocrisy" , "With genuine feeling" , "With genuine feelings" , "Genuinely, honestly" , "Last word in letter" .)