A hat with the flatest of brims...not an ordinary baseball cap. Gives user high amounts of swag.
Look at that bro over there, he has so much swag in his flat bill.
The gay ass way that people wear their hats nowadays. They even leave on the gay ass round shiny stickers that tell you how small the casing for your brain is. You used to shape your bill into a curved thing that would fit snugly on your head...back when it was cool to wear a hat.
"Damn foo, look at all those wannabee gangsta's flatbillin it!"
"I can't believe you're using a flat bill...you used to be cool!"