Definitions by WILD YAMAHA RIDER

dirtbike 

An off-road motorcycle a.k.a.bike used in the dirt dirt often desribed with numbers (125) wich is the CC (cubic centimeters) of the engine

so dirt+bike= dirtbike

Honda, Yamaha, Kawasaki, Suzuki

dirtbike by WILD YAMAHA RIDER October 18, 2003