Island within Aruba limits (4)
I believe the answer is:
bali
'island' is the definition.
(Bali is an example)
'within aruba limits' is the wordplay.
'within' indicates the answer is hidden within the clue.
'BALI' is hidden in the letters of 'aruba limits'.
(Other definitions for bali that I've seen before include "mountainous island" , "Javanese island" , "Indonesian island, capital Denpasar" , "Island in Indonesia" , "Bail out of the island" .)