A combination of "heinous" and "gnarly". Used to describe something that is both very difficult, painful, or dangerous (heinous) and sick, cool, awe-inspiring (gnarly). Most common usage in the extreme sports world.
"Travis Pastrana's double backflip in the X-games was heingnar"
also
"I cant believe that you just threw down a 360air over that pit of lava while being shot at with pellet guns; that was so heingnar!"
To "Heizenmoab" is to churn ones insides back and forth until you replace all their blood with your cum and slowly their blood will seep out of their eyes.