An instant of intense acts of complete or total gnar-ness. A barrage of awe producing events characterized by being cool,fast, dangerous and/or violently agressive. Commonly used among skateboarders.
"Dude, did you see the slams part in the vid?"
"Yeah! Everyone got so wrecked...straight gnarbarge son!"
"and the show?"
"You should have been there! One band was complete thrash. Their set was gnarbarge!"