A good doctor has fish; confusing! (7)
I believe the answer is:
addling
'confusing' is the definition.
(addling is a kind of confusing)
'a good doctor has fish' is the wordplay.
'good doctor' becomes 'dd' (Doctor of Divinity. I am not sure about the 'good' bit.).
'has' is a charade indicator (letters next to each other).
'fish' becomes 'ling' (ling is a kind of fish).
'a'+'dd'+'ling'='ADDLING'
Can you help me to learn more?
(Other definitions for addling that I've seen before include "Becoming rotten" , "Taking order from" .)