aft vs piggyback

aft

adj
  • located at the back of a boat, ship, or airplane 

noun
  • The stern portion of a vessel. 

adv
  • At, near, or towards the stern of a vessel (with the frame of reference within the vessel). 

piggyback

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

  • On somebody's back or shoulders. 

  • Attached or appended to something larger or more important. 

noun
  • An act or instance of piggybacking. 

  • The connection of one intravenous drip to another. 

  • A ride on somebody's back or shoulders. 

adv
  • On somebody's back or shoulders. 

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. 

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