Nut in Southern pies (5)
I believe the answer is:
pecan
'nut in southern pies' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for pecan that I've seen before include "Oval nut of south central United States" , "Type of nut" , "Walnut-like nut" , "nut-tree" , "Species of hickory - edible nut" .)