pistache

noun, plural pis·tach·i·os.

1. the nut of a Eurasian tree, Pistacia vera, of the cashew family, containing an edible, greenish kernel.
2. the kernel itself, used for flavoring.
3. the tree itself.
4. pistachio nut flavor.
5. pistachio green.

noun plural -os

1. an anacardiaceous tree, Pistacia vera, of the Mediterranean region and W Asia, with small hard-shelled nuts
2. Also called: pistachio nut the nut of this tree, having an edible green kernel
3. the sweet flavour of the pistachio nut, used esp in ice creams

adjective

4. of a yellowish-green colour

n.1590s, from Italian pistacchio, from Latin pistacium “pistachio nut,” from Greek pistakion “pistachio nut,” from pistake “pistachio tree,” from Persian pistah “pistachio.” Borrowed earlier (1530s) as pystace, from Old French form pistace (13c.), which also is from the Italian word.