on the european plan

from The Collaborative International Dictionary of English v.0.48

European \Eu`ro*pe"an\, prop. a. [L. europeaus, Gr. ?, fr. Gr. ?
   (L. europa.)]
   Of or pertaining to Europe, or to its inhabitants.
   [1913 Webster]

   {On the European plan}, having rooms to let, and leaving it
      optional with guests whether they will take meals in the
      house; -- said of hotels. [U. S.]
      [1913 Webster]