juggernaut vs prime mover

juggernaut

noun
  • A large, cumbersome truck or lorry, especially an artic. 

  • An institution that incites destructive devotion or to which people are carelessly sacrificed. 

  • A literal or metaphorical force or object regarded as unstoppable, that will crush all in its path. 

prime mover

noun
  • A military or heavy construction vehicle. 

  • 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. 

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

  • 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 

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