canal vs trunking

canal

noun
  • A tubular channel within the body. 

  • An artificial waterway or artificially improved river used for travel, shipping, or irrigation. 

  • One of the faint, hazy markings resembling straight lines on early telescopic images of the surface of Mars. 

verb
  • To dig an artificial waterway in or to (a place), especially for drainage 

  • To travel along a canal by boat 

trunking

noun
  • A system of ducts for cables, heating or ventilation. 

  • The movement of containers or packages between a terminal and a transporter's inland facilities, or the scheduled transportation service between locations. 

  • All the electrical and communications cables bundled together and distributed through a building. 

  • Plastic conduit or duct used to conceal and protect electrical wiring. 

  • A two-way radio technique that uses a control channel to automatically assign frequency channels to groups of user radios. 

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