Performed with a high degree of skill (12)
I believe the answer is:
accomplished
'skill' is the definition.
(I've seen this before)
'performed with a high degree of' is the wordplay.
I cannot quite understand how this works, but
'a' is found in the answer.
'high' could be 'h' (abbreviation) and 'h' is present in the answer.
'degree' could be 'c' (C is an example) and 'c' is found within the answer.
'of' could be 'o' and 'o' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for accomplished that I've seen before include "Highly skilled" , "executed" , "Highly proficient" , "Talented - performed" , "Completed; skilful" .)