{ or }, n. A two-wheeled vehicle having a motor attached so as to be self-propelled. In common usage, a motorcycle is of heavier construction with larger wheels, a more powerful motor, and a higher maximum speed than a motorbike. A motorcycle may have a small appended compartment called a sidecar, supported by a third wheel, which can carry a passenger. [ Webster 1913 Suppl. ]

In Great Britain as of 1913 the term motor cycle was treated by statute (3 Ed VII. c. 36) as limited to motor cars (self-propelled vehicles) designed to travel on not more than three wheels, and weighing unladen (that is, without water, fuel, or accumulators necessary for propulsion) not more than three hundred weight (336 lbs.). [ Webster 1913 Suppl. ]