1 an evergreen tree, Pistacia vera, bearing small brownish-green flowers and ovoid reddish fruit.
2 (in full pistachio nut) the edible pale-green seed of this.
3 a pale green colour.
Etymology: It. pistaccio and Sp. pistacho f. L pistacium f. Gk pistakion f. Pers. pistah
Useful english dictionary. 2012.