A person, usually an American, who gets all their information from
mainstream media such as Fox News or CNN, or other corporate-sponsored media. This often leads to a case of Dunning-Krueger effect, since mediaheads view themselves as highly intelligent and informed simply because they think they keep up with current events
around the world, but in reality they usually lack any real depth of knowledge, believe that anything they didn't hear on Bill O'Reilly or
The Daily Show is false, and are viewed as silly by most of the rest of the world.
A mediahead probably still thinks that
George Bush found WMDs in Iraq and that 9/11 only happened because Muslims hate us for our freedom, or that
Donald Trump, who's best known as a game show host, is secretly an evil fascist genius who's leading a vast alt-right
white supremacist conspiracy to re-instate Jim Crow.