juggernaut vs tractor-trailer

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. 

tractor-trailer

noun
  • A large truck consisting of an engine and cab section (the tractor) and a cargo-carrying semi-trailer or trailer. 

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