confidential

adjective | \ ˌkän-fi-ˈden-chəl \ | con·fi·den·tial
  1. : known or conveyed only to a limited number of people a confidential disclosure

  1. : marked by or indicative of intimacy, mutual trust, or willingness to confide especially between parties one of whom is in a position of superiority the confidential relationship of doctor and patient

  1. : containing information whose unauthorized disclosure could be prejudicial to the national interest