The Collaborative International Dictionary of English v.0.48:

Sicca \Sic"ca\, n. [Ar. sikka.]
   A seal; a coining die; -- used adjectively to designate the
   silver currency of the Mogul emperors, or the Indian rupee of
   192 grains.
   [1913 Webster]

   Sicca rupee, an East Indian coin, valued nominally at about
      two shillings sterling, or fifty cents.
      [1913 Webster]