n. (pl. -os) 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.
[ It. pistaccio and Sp. pistacho f. L pistacium f. Gk pistakion f. Pers. pistah ]