Semi-capricious resort isle (5)
I believe the answer is:
capri
'isle' is the definition.
(Italian island)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for capri that I've seen before include "I carp about the island" , "Romantic Isle in Bay of Naples" , "Italian isle" , "Island near Naples" , "Island off Italy" .)