Politicians release top Mafiosi from Palermo, for instance (8)
I believe the answer is:
sicilian
'instance' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for sicilian that I've seen before include "A chess opening; one from Palermo" , "Mafioso may be" , "Native of Palermo, say" , "of Mafia origin" , "Native or large island off the toe of Italy" .)