motor vs prime mover

motor

noun
  • A machine or device that converts other energy forms into mechanical energy, or imparts motion. 

  • The fermenting mass of fruit that is the basis of pruno, or "prison wine". 

  • A motor car, or automobile, even a goods vehicle. 

  • A source of power for something; an inspiration; a driving force. 

  • Any protein capable of converting chemical energy into mechanical work. 

adj
  • Relating to motor cars. 

  • Propelled by an internal combustion engine (as opposed to a steam engine or turbine). 

  • Relating to the ability to move. 

verb
  • To rotate a jet engine or turboprop using the engine's starter, without introducing fuel into the engine. 

  • To progress at a brisk pace. 

  • To leave. 

prime mover

noun
  • A machine, such as a water wheel or steam engine, that receives and modifies energy as supplied by some natural source or fuel and transforms it into mechanical work 

  • A person or thing that is seminal and influential. 

  • The front part of a semi-trailer type truck, i.e., the tractor to which the trailer part attaches. 

  • A military or heavy construction vehicle. 

  • The initial agent that is the cause of all things. 

How often have the words motor and prime mover occurred in a corpus of books? (source: Google Ngram Viewer )