The Collaborative International Dictionary of English v.0.48:

Pataca \Pa*ta"ca\, n. [Sp.]
   The Spanish dollar; -- called also patacoon. [Obs.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Patacoon \Pa`ta*coon"\, n. [Sp.]
   See Pataca.
   [1913 Webster]