Rude hack disturbed European nobleman (8)
I believe the answer is:
archduke
'european nobleman' is the definition.
(I've seen this before)
'rude hack disturbed' is the wordplay.
'disturbed' is an anagram indicator (the order of letters is disturbed).
'rude'+'hack'='rudehack'
'rudehack' is an anagram of 'ARCHDUKE'.
(Other definitions for archduke that I've seen before include "noted trio" , "Prince of the former ruling house of Austria, Ferdinand for one" , "Top nobleman" , "Emperor's son" , "European nobleman" .)