“Fake news” means knowingly publishing something that is not true or knowingly not publishing something that is true.
News media non-coverage of the recent Maryland high school rape case is a glaring example of fake news. Good analysis in the link below of this crime and how it is not being reported due to political bias.
A great deal of fake news involves what is not reported. Controlling what stories the public sees to support a political agenda is propaganda, not news.