Say further with resolution and observe intended recipient (9)
I believe the answer is:
addressee
'intended recipient' is the definition.
(I've seen this before)
'say further with resolution and observe' is the wordplay.
'say further' becomes 'add' (I've seen this in another clue).
'with' is a charade indicator (letters next to each other).
'resolution' becomes 'res' (I've seen this in other clues).
'and' is a charade indicator (letters next to each other).
'observe' becomes 'see' (observe can mean to see something).
'add'+'res'+'see'='ADDRESSEE'
(Other definitions for addressee that I've seen before include "one who's likely to get the post" , "Intended recipient of letter" , "He gets a letter" , "One contacted" , "He's written to" .)