PISTACHIO

[pis.ta.chio] n, pl -chios [It pistacchio, fr. L pistacium pistachio nut, fr. Gk pistakion, fr. pistake pistachio tree, of Iranian origin; akin to Pers pistah pistachio tree] (1598): a small Asian tree (Pistacia vera) of the cashew family whose drupaceous fruit contains a greenish edible seed; also: its seed