referendum

referendum
    n 1: a legislative act is referred for final approval to a
         popular vote by the electorate
    

Referendum \Ref`er*en"dum\ (r?f`?r*?n"d?m), n.; pl. {-da}
   [Gerundive fr. L. referre. See {Refer}.]
   1. A diplomatic agent's note asking for instructions from his
      government concerning a particular matter or point.
      [1913 Webster]

   2. The right to approve or reject by popular vote a meassure
      passed upon by a legislature.
      [1913 Webster]

   3. The principle or practice of referring measures passed
      upon by the legislative body to the body of voters, or
      electorate, for approval or rejection, as in the Swiss
      cantons (except Freiburg) and in various local governments
      in the United States, and also in the local option laws,
      etc.; also, the right to so approve or reject laws, or the
      vote by which this is done. Referendum is distinguished
      from the mandate, or instruction of representatives by the
      people, from direct government by the people, in which
      they initiate and make the laws by direct action without
      representation, and from a plebiscite, or popular vote
      taken on any measure proposed by a person or body having
      the initiative but not constituting a representative or
      constituent body.
      [Webster 1913 Suppl.]
    

REFERENDUM, n.  A law for submission of proposed legislation to a
popular vote to learn the nonsensus of public opinion.
    

REFERENDUM, international law. When an ambassador receives propositions 
touching an object over which he has no sufficient power and he is without 
instruction, he accepts it ad referendum, that is, under the condition that 
it shall be acted upon by his government, to which it is referred. The note 
addressed in that case to his government to submit the question to its 
consideration is called a referendum. 
    

83 Moby Thesaurus words for "referendum":
      Australian ballot, Hare system, aye, ballot, by-election, canvass,
      canvassing, casting vote, caucus, closed primary,
      congressional election, constitutional referendum,
      contested election, counting heads, cumulative voting,
      deciding vote, direct initiative, direct primary, division,
      election, enfranchisement, facultative referendum, fagot vote,
      franchise, general election, graveyard vote, hand vote,
      indirect initiative, initiative, list system, mandate,
      mandatory primary, mandatory referendum, nay, no,
      nonpartisan primary, nontransferable vote, open primary,
      optional primary, partisan election, plebiscite, plebiscitum,
      plumper, plural vote, poll, polling, preference primary,
      preferential voting, presidential election,
      presidential preference primary, presidential primary, primary,
      primary election, proportional representation, proxy, recall,
      record vote, representation, right to vote, rising vote, runoff,
      runoff election, runoff primary, say, secret ballot, show of hands,
      single vote, snap vote, statutory referendum, straw vote, suffrage,
      transferable vote, viva voce, voice, voice vote, vote, voting,
      voting right, write-in, write-in vote, yea, yeas and nays, yes