A little kid that plays the game Guitar Hero way too much and then thinks that they are cool because they listen to rock music. But truly, they don't know any songs other than the ones in the game.
"Man, your brother is such a guitar hero poser, he thinks he's badass because he knows one song by Megadeth."
Any person of another race (other than black) that hangs out and associates with black people most of the time and is accepted by them makes them black by association.
"Dude, are we gonna get shot?"
"Chill out dude, I'm black by association."