European principality (6)
I believe the answer is:
monaco
'european principality' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for monaco that I've seen before include "Mediterranean principality" , "Home of the Grimaldis" , "Independent principality on the French Riviera" , "Principality within France" , "Principality of the Rainiers" .)