flicker vs snorkel

flicker

verb
  • To flutter or flap. 

  • To burn or shine unsteadily, or with a wavering light. 

  • To keep going on and off; to appear and disappear for short moments; to flutter. 

noun
  • Any of certain small woodpeckers, especially of the genus Colaptes. 

  • One who flicks. 

  • An unsteady flash of light. 

  • A short moment. 

snorkel

verb
  • To use a snorkel. 

noun
  • A snorkel parka. 

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

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

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