As an adjective pistic
is having faith; trusting.
As a noun pistick is
a pistachio nut (also used attributively).
pistick
English
Noun
(
en noun)
(obsolete) A pistachio nut (also used attributively).
*, II.ii.1.1:
*:Trallianus discommends figs, Salvianus olives and capers, which others especially like of, and so of pistick nuts.