pis‧ta‧chi‧o /pəˈstɑːʃiəʊ, pɪˈstɑːʃiəʊ $ pəˈstæʃioʊ/ BrE AmE noun (plural pistachios) [countable]
[Date: 1400-1500; Language: Italian; Origin: pistacchio, from Latin, from Greek pistakion, from pistake 'pistachio tree', from Persian pistah]
a small green nut:
pistachio ice cream
1.(alsopiˈstachio nut)countable the small green nut of an Asian tree
2.uncountable a pale green colour Word Origin:
late Middle English pistace, from Old French, superseded in the 16th cent. by forms from Italian pistaccio, via Latin from Greek pistakion, from Old Persian.