Island of cannibalism (4)
I believe the answer is:
bali
'island' is the definition.
(Indonesian island)
'of cannibalism' is the wordplay.
'of' says the answer is hidden in the clue.
'BALI' is hidden within 'cannibalism'.
(Other definitions for bali that I've seen before include "Indonesian island, east of Java" , "Javanese island" , "Indonesian holiday destination" , "mountainous island" , "Middle East country" .)