A male usually a skateboarder/snowboarder who has past the height of his youth, but shows no remorse or value for the safety of his body. Gnardoggs usually sport facial hair, plaid western shirts, brown corduroy pants, and a beanie. They drink a lot, smoke a lot, and live hard.
Yo! Check that gnardogg down that 40oz then pummel that pool like it's nothing. He just got coping man! GNARRR