Accused worker after notes finish (9)
I believe the answer is:
defendant
'accused' is the definition.
(I know that accused can be written as defendant)
'worker after notes finish' is the wordplay.
'worker' becomes 'ant' (worker is a type of ant).
'after' means one lot of letters go next to another.
'notes finish' becomes 'defend' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'ant' after 'defend' is 'DEFENDANT'.
Can you help me to learn more?
(Other definitions for defendant that I've seen before include "One charged" , "Person accused" , "The one before the court" , "Against whom an action is brought in a law court" .)