canal vs snorkel

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 

snorkel

noun
  • A hollow tube, held in the mouth, or mounted on and opening into a diving mask, used by swimmers for breathing underwater. 

  • A snorkel parka. 

  • A retractable tube fitted in diesel-engine submarines to allow sufficient ventilation that the engines may be used at periscope depth. 

verb
  • To use a snorkel. 

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