A person who rides any two-wheeled motorized vehicle(scooter, motorcycle, etc.) without a helmet. The word comes from the flower arrangements placed on the side of the road where a deadly accident occured.
"Dude! Did you see that guy in the motorcyle? He had to be going at least a hundred!" "Yea, I also noticed he was wearing jean-shorts and a tank top with no helmet. Regular Roadside Bouquet.