Indistinct note to a king (5)
I believe the answer is:
blear
'indistinct' is the definition.
(I've seen this in another clue)
'note to a king' is the wordplay.
'note' becomes 'b' (musical note).
'to a king' becomes 'lear' (King Lear).
'b'+'lear'='BLEAR'
(Other definitions for blear that I've seen before include "Indistinct" , "Watery, blurred" , "Make (the eyes) dim" , "Baler (anag.)" , "Blur" .)