[1] : The Collaborative International Dictionary of English v.0.48

pistache \pistache"\, n. oe. pistace, fr. f. pistache. see
   pistachio. bot.
   the anacardiaceous tree pistacia vera, which yields the
   pistachio nut; also, the nut itself and the flavoring extract
   prepared from it. called also pistachio.
   webster 1913 suppl.
see also:
pistachio pistacia vera pistachio 

[2] : The Collaborative International Dictionary of English v.0.48

pistachio \pista"chio\, n. it. pistacchio cf. sp. pistacho,
   f. pistache, fr. l. pistacium, gr. ?, ?, fr. per. pistah.
   cf. fistinut. bot.
   the nut of the pistacia vera, a tree of the order
   anacardiaceae, containing a kernel of a pale greenish
   color, which has a pleasant taste, resembling that of the
   almond, and yields an oil of agreeable taste and odor; --
   called also pistachio nut. it is wholesome and nutritive.
   the tree grows in arabia, persia, syria, and sicily. written
   also pistachia.
   1913 webster

   2. the small anacardiaceous tree pistacia vera, of
      southern europe and asia minor, which bears the pistachio
      nut. called also pistache.
      webster 1913 suppl.

   3. cookery the flavor of the pistachio nut, or an ice or
      confection flavored with it.
      webster 1913 suppl.

   4. pistachio green.
      webster 1913 suppl.
see also:
fistinut pistacia vera anacardiaceae pistachio nut pistachia pistache 

[3] : WordNet (r) 2.0

pistachio
     n 1: small tree of southern europe and asia minor bearing small
          hard-shelled nuts syn: pistacia vera, pistachio tree
     2: nut of mediterranean trees having an edible green kernel
        syn: pistachio nut
see also:
pistacia vera pistachio tree pistachio nut 

Pistachio >> P Words
Pistachio, definition of term: Pistachio
pistachio_pag1.html

Pistachio Nut >> P Words
Pistachio Nut, definition of term: Pistachio Nut
pistachio+nut_pag1.html