More prudent coastal state trapped wolf (9)
I believe the answer is:
womaniser
'wolf' is the definition.
(I've seen this before)
'more prudent coastal state trapped' is the wordplay.
'more prudent' becomes 'wiser' ('wise' can be similar in meaning to 'prudent').
'coastal state' becomes 'oman' (Oman is a country. I am not sure about the 'coastal' bit.).
'trapped' means one lot of letters goes inside another.
'wiser' enclosing 'oman' is 'WOMANISER'.
Can you help me to learn more?
(Other definitions for womaniser that I've seen before include "A rake" , "Playboy" , "Casanova" , "Don Juan" , "Lady-killer" .)