Discourage the German bringing in note (5)
I believe the answer is:
deter
'discourage' is the definition.
(synonyms)
'the german bringing in note' is the wordplay.
'the german' becomes 'der' ('the' in German).
'bringing in' indicates putting letters inside.
'note' becomes 'te' (musical note).
'der' enclosing 'te' is 'DETER'.
(Other definitions for deter that I've seen before include "Discourage or prevent from doing something" , "Cause not to do something" , "Check" , "Discourage or impede" , "Discourage (someone from an action)" .)