1. Anyone who consistently and repeatedly validates their personal beliefs simply by regurgitating the opinions, thoughts, speech and or writings of others.
2. The more inclusive and expanded variant of "dittohead."
A realhead is an individual who is aware of the facts of the discussion. They know what happened and they know what's going on. They see through lies with the logic of a Vulcan. Ergo they know what the fuck is up and they are down with the real shit.
Realheads will remember that Octavian's adoptive father Julius Caesar had received the same honour of having his body declared sacrosanct under Roman law and Roman religion as if he were a Tribune of the Plebs.