Generally from the nothern california region. One who drives lifted trucks with nor cal stickers on the back window. Not to mention rides motocross or bmx. They often wear DC shoes, long socks, small shirts, generic spy sunglasses, dickie's shorts with studded belts and oversised belt buckles. Popular brands worn by SNBBs would be fox, shift, skin, famous stars and straps, DC, etnies, and dickie's. They usually wear undersised shirts and have strange tatoos and piercings.
Billy calls things "hella sick" and fits the discription above. Little Billy is a sick nasty bro bro.
Trevor enjoys wearing fake lip piercings and riding his motocross bike. Trevor is definitely a sick nasty bro bro.
Timothy idolizes rick thorne and travis barker, he is probably a sick nasty bro bro.
A characteristic or thing that fits the sick nasty bro bro style, or is just flat out stupid can also be called sick nasty.