Pecan or pistachio (3)
I believe the answer is:
nut
This clue is a double definition.
'pecan' is the first definition.
(I've seen this in another clue)
'pistachio' is the second definition.
(thesaurus)
(Other definitions for nut that I've seen before include "Hard-skinned fruit" , "Vegetarian food" , "Butt" , "Head (slang)" , "organized teachers" .)