The note below says "To Wash" (7)
I believe the answer is:
launder
'wash' is the definition.
(I know that wash can be written as launder)
'the note below' is the wordplay.
'the note' becomes 'la' (musical note as in do-re-mi).
'below' becomes 'under' (synonyms).
'la'+'under'='LAUNDER'
'says to' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for launder that I've seen before include "Make clean, clothing or money" , "Cleanse (material or money)" , "Perhaps decriminalise" , "Wash or cleanse, clothes or money" , "Convert illegal funds into legal ones" .)