Used in conjuction with the verb to "GH", or to play the video game Guitar Hero. The GH'er is the person(s) currently playing the game. The person must also be competent enough to play on hard or expert to be a true GH'er. Can be used in many verb forms.
"So CJ are you GH'ing later?"
"Dude with that guitar in your hand you look like a straight GH'er"