Definition of motor-cycle:
(n) :
A machine or device that converts other energy forms into mechanical energy, or imparts motion.
(n) :
(now colloquial outside attributive use) A motor car, or automobile, sometimes extended to other powered vehicles, such as goods vehicles.
(n) :
(figuratively) A source of power for something; an inspiration; a driving force.
(adj) :
(biology) Relating to the ability to move.
(adj) :
(nautical) Propelled by an internal combustion engine (as opposed to a steam engine or turbine).
(v) :
(informal, figurative) To progress at a brisk pace.