Source : Webster's Revised Unabridged Dictionary (1913)

Zollverein \Zoll"ve*rein`\, n. [G., from zoll duty + verein
   union.]
   Literally, a customs union; specifically, applied to the
   several customs unions successively formed under the
   leadership of Prussia among certain German states for
   establishing liberty of commerce among themselves and common
   tariff on imports, exports, and transit.

   Note: In 1834 a zollverein was established which included
         most of the principal German states except Austria.
         This was terminated by the events of 1866, and in 1867
         a more closely organized union was formed, the
         administration of which was ultimately merged in that
         of the new German empire, with which it nearly
         corresponds territorially.