Woo Sean Duff's mistress (9)
I believe the answer is:
courtesan
'mistress' is the definition.
(I know that mistress can be written as courtesan)
'woo sean duff's' is the wordplay.
I cannot quite understand how this works, but
'woo' could be 'court' (synonyms) and 'court' is found in the answer.
an anagram of 'sean' is 'esan' which is located in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for courtesan that I've seen before include "lover" , "loose woman" , "High-class prostitute" , "Prostitute - mistress of high-ranking man" , "Fanny Hill, perhaps" .)