Noun
a major social class or order of persons regarded collectively as part of the body politic of the country (especially in the United Kingdom) and formerly possessing distinct political rights
Source: WordNetThe gallery in which the reporters sit has become a fourth estate of the realm. Thomas Babington Macaulay
According to WPV, the media, as the Fourth Estate of the Realm, must not allow itself to be used as a tool that will ignite political, ethnic and religious violence. Source: Internet