Wild animal in European capital starts to scare Brits off (4)
I believe the answer is:
lion
'wild animal' is the definition.
I don't understand the remainder of the clue.
(Other definitions for lion that I've seen before include "Carnivorous 6" , "King of sorts" , "Leo" , "Sought after celebrity (showing great strength and courage?)" , "Animal which Judah is described as" .)