/pi stash"ee oh', -stah"shee oh'/ , n. , pl. pistachios .
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. See pistachio green .
Also, pistache /pi stash"/ , pistachio nut (for defs. 1, 2).
[ 1375-1425; pistacchio pistacium pistákion pistachio nut, dim. of pistáke pistachio tree pistak (Pers pista ); r. late ME pistace ]