Often can be seen at places such as Burning Man and Bonaroo.
Typically a men's look involving sandals, cut offs, dirty, oversized, or stained items. Bad grooming, farmers tans and beards are also common.
Celebrity sporting this look: "The Dude" From the Big Lebowski.
Antonym: Hipster. Stoner Casual defines those who do not intentionally look ironic or unkept, but those who actually default to this look based on lack of taste, style and cleanliness.