Hickory (5)
I believe the answer is:
pecan
'hickory' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for pecan that I've seen before include "Oval nut of south central United States" , "Smooth pinkish-brown nut, nice in pie" , "Nut with sweet oily kernel" , "Type of nut" , "Nut of American hickory tree" .)