Pistachio or almond (3)
I believe the answer is:
nut
This clue is a double definition.
'pistachio' is the first definition.
(thesaurus)
'almond' is the second definition.
(almond is a type of nut)
(Other definitions for nut that I've seen before include "Almond, for example" , "Brazil, for instance" , "keen admirer" , "Freak" , "Screwball" .)