coach vs railroad truck

coach

noun
  • A wheeled vehicle, generally drawn by horse power. 

  • The part of a commercial passenger airplane or train reserved for those paying the lower standard fares; the economy section. 

  • The lower-fare service whose passengers sit in this part of the airplane or train; economy class. 

  • The forward part of the cabin space under the poop deck of a sailing ship; the fore-cabin under the quarter deck. 

  • A trainer or instructor. 

  • A long-distance, or privately hired, bus. 

  • A passenger car, either drawn by a locomotive or part of a multiple unit. 

verb
  • To instruct; to train. 

  • To train. 

  • To travel in a coach (sometimes coach it). 

  • To convey in a coach. 

  • To study under a tutor. 

adv
  • Via the part of a commercial passenger airplane or train reserved for those paying the lower standard fares; via the economy section. 

railroad truck

noun
  • A chassis or framework-like structure underneath a railroad car to which wheel axles (and, hence, wheels) are attached through bearings. (Not to be confused with railway truck or railtruck, which are British English synonyms of railroad car) 

How often have the words coach and railroad truck occurred in a corpus of books? (source: Google Ngram Viewer )