Well-bred man possibly shocking swimmer (7)
I believe the answer is:
genteel
'well-bred' is the definition.
(I've seen this in another clue)
'man possibly shocking swimmer' is the wordplay.
'man possibly' becomes 'gent' (gent is a kind of man. I am not sure about the 'possibly' bit.).
'shocking swimmer' becomes 'eel' (I've seen this in another clue).
'gent'+'eel'='GENTEEL'
Can you help me to learn more?
(Other definitions for genteel that I've seen before include "Mannerly" , "Terribly polite" , "Affectedly refined and upper-crust" , "Well mannered" , "Polite and well-bred" .)