piggyback vs tram

piggyback

verb
  • To transport (a lorry/truck) on a flatbed railway waggon 

  • To utilize "last-mile" wiring rented from a larger owner ISP by a smaller ISP. 

  • To obtain a wireless internet connection by bringing one's own computer within the range of another's wireless connection without that subscriber's permission or knowledge. 

  • To carry (someone) on the back or shoulders. 

  • To enter a secured area at the same time along with someone having authorized access; to tailgate 

  • To attach or append something to another (usually larger) object or event. 

noun
  • An act or instance of piggybacking. 

  • The connection of one intravenous drip to another. 

  • A ride on somebody's back or shoulders. 

adj
  • On somebody's back or shoulders. 

  • Pertaining to transportation of goods where one transportation unit is carried on the back of something else. For example, a truck on a train. 

  • Attached or appended to something larger or more important. 

adv
  • On somebody's back or shoulders. 

tram

verb
  • To transport (material) by tram. 

  • To weave in this manner. 

  • To travel by tram. 

  • To operate, or conduct the business of, a tramway. 

  • To align a component in mechanical engineering or metalworking, particularly the head of a drill press. 

noun
  • A similar vehicle for carrying materials. 

  • An aerial cable car. 

  • A train with wheels that runs on a road; a trackless train. 

  • A people mover. 

  • A car on a horse railway or tramway (horse trams preceded electric trams). 

  • A silk thread formed of two or more threads twisted together, used especially for the weft, or cross threads, of the best quality of velvets and silk goods. 

  • A passenger vehicle for public use that runs on tracks in the road (called a streetcar or trolley in North America). 

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