Leave Adriatic resort (5)
I believe the answer is:
split
This clue is a double definition.
'leave' is the first definition.
(I've seen this before)
'adriatic resort' is the second definition.
(Croatian city)
(Other definitions for split that I've seen before include "Balkan town" , "Leave - crack" , "shared by a couple?" , "ice cream concoction" , "Divide into portions" .)