bombination vs tremble

bombination

noun
  • the act or sound of humming or buzzing; hum, buzz 

tremble

noun
  • A shake, quiver, or vibration. 

verb
  • To shake, quiver, or vibrate. 

  • To fear; to be afraid. 

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