(Noun) An individual that wears the bill of their hat completely flattened out so that other douchebags will know that he is also just pretending that he knows martial arts.
This style of headgear is frequently worn with clothing and accessories that prominently feature the Tapout logo and tattoos that say 'I'm a douche" in Chinese lettering next to tribal armbands.
Note: Less than 31% of flathats actually know any kind of martial arts and even fewer actually own a motorcycle.
Did you see those two flathats get their asses kicked by that Yoga Instructor chick that they were hitting on? I guess they bought the MMA gear but couldn't afford the lessons.