European Pope defending rogue pleasure-seeker (8)
I believe the answer is:
epicurus
'pleasure-seeker' is the definition.
(I've seen this before)
'european pope defending rogue' is the wordplay.
'european' becomes 'e' (abbreviation e.g. EU).
'pope' becomes 'pius' (pope pius xii).
'defending' is an insertion indicator.
'rogue' becomes 'cur' (I've seen this in other clues).
'pius' going around 'cur' is 'picurus'.
'e'+'picurus'='EPICURUS'
(Other definitions for epicurus that I've seen before include "Greek philosopher who considered pleasure a goal" , "pleasure-seeker" , "Ancient Greek philosopher" .)