Extra piece of work accepted by me (4)
I believe the answer is:
more
'extra' is the definition.
(both can mean additional)
'piece of work accepted by me' is the wordplay.
I cannot quite see how this works, but
'piece' could be 'r' (abbreviation for Rook) and 'r' is located in the answer.
'of' could be 'o' and 'o' is found in the answer.
'me' is present in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for more that I've seen before include "A greater amount" , "victim of Henry" , "Writer" , "author" , "Greater quantity or number" .)