Who knows the definition, but I can tell you who is included. ABC, NBC, CBS, CNN.... Watching the anchors on these channels respond to Trumps performance on election night was jaw dropping. I was amazed that they weren't even going to try to pretend that they were impartially covering this election. I've always known the Fox and msnbc were a joke, but I have zero confidence in a single US based news outlet after this election.

BTW Huffington Post stands out as an exceptionally huge steaming pile of partisan garbage as well.