third party: Meaning and Definition of

third' par'ty

Pronunciation: [key]
  1. any party to an incident, case, quarrel, etc., who is incidentally involved.
  2. (in a two-party system) a political party formed as a dissenting or independent group from members of one or both of the two prevailing major parties.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.