A light road carriage propelled by the feet of the
   rider. Originally it was propelled by striking the tips of the toes on
   the roadway, but commonly now by the action of the feet on a pedal or
   pedals connected with the axle of one or more of the wheels, and
   causing their revolution. They are made in many forms, with two, three,
   or four wheels. See Bicycle, and Tricycle.