From The Collaborative International Dictionary of English v.0.48 [gcide]:
Pistole \Pis*tole"\, n. [F., probably a name given in jest in
France to a Spanish coin. Cf. Pistol.]
The name of certain gold coins of various values formerly
coined in some countries of Europe. In Spain it was
equivalent to a quarter doubloon, or about $3.90, and in
Germany and Italy nearly the same. There was an old Italian
pistole worth about $5.40.
[1913 Webster]