Islander’s strange trance (6)
I believe the answer is:
cretan
'islander's' is the definition.
(someone from Crete)
'strange trance' is the wordplay.
'strange' is an anagram indicator.
'trance' anagrammed gives 'CRETAN'.
(Other definitions for cretan that I've seen before include "Native of Minoan island" , "Native of Greek island south of mainland (6)" , "One comes from a Mediterranean island" , "A Mediterranean islander" , "Of a Greek island, centre of the Minoan civilisation" .)