The note, you guarantee, will be disapproving (7)
I believe the answer is:
censure
'will be disapproving' is the definition.
I can't judge whether this defines the answer.
'the note you guarantee' is the wordplay.
'the note you' becomes 'c' (I am not sure about this - if you are sure you should believe this answer much more).
'guarantee' becomes 'ensure' (synonyms).
'c'+'ensure'='CENSURE'
Can you help me to learn more?
(Other definitions for censure that I've seen before include "Rebuke formally" , "Formally reprove" , "Official reprimand" , "Castigation" , "Rebuke, strongly criticise" .)