Sicilian fortified wine (7)
I believe the answer is:
'sicilian fortified wine' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for marsala that I've seen before include "Fortified Sicilian wine" , "Dessert wine from Sicily" , "Sweet dessert wine" , "Sweet Sicilian wine" , "Alcoholic drink" .)