flicker vs tremble

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. 

tremble

verb
  • To shake, quiver, or vibrate. 

  • To fear; to be afraid. 

noun
  • A shake, quiver, or vibration. 

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