New earnings docked before river work for Charlie (10)
I believe the answer is:
nincompoop
'new earnings docked before' is the definition.
I can't judge whether this definition defines the answer.
'river work for charlie' is the wordplay.
'river' becomes 'Po River' (Italian river).
'work' becomes 'op' (common abbreviation for 'opus').
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'charlie' becomes 'nincom' (I can't explain this - if you can you should give a lot more credence to this answer).
'po'+'op'='poop'
'poop' put after 'nincom' is 'NINCOMPOOP'.
Can you help me to learn more?
(Other definitions for nincompoop that I've seen before include "dunce" , "Twit" , "Idiot" , "Foolish person" , "Fool" .)