The Collaborative International Dictionary of English v.0.48:

Rix-dollar \Rix"-dol`lar\, n. [Sw. riksdaler, or Dan. rigsdaler,
   or D. rijksdaalder, or G. reichsthaler, literally, dollar of
   the empire or realm, fr. words akin to E. rich, and dollar.
   See Rich, Dollar.]
   A name given to several different silver coins of Denmark,
   Holland, Sweden,, NOrway, etc., varying in value from about
   30 cents to $1.10; also, a British coin worth about 36 cents,
   used in Ceylon and at the Cape of Good Hope. See Rigsdaler,
   Riksdaler, and Rixdaler.
   [1913 Webster]

   Note: Most of these pieces are now no longer coined, but some
         remain in circulation.
         [1913 Webster]