scratching vs tremble

scratching

noun
  • The act or sound of something being scratched. 

  • Record scratching, a technique of starting and stopping a vinyl record from playing to produce music in hip hop. 

  • A pork scratching. 

tremble

noun
  • A shake, quiver, or vibration. 

verb
  • To shake, quiver, or vibrate. 

  • To fear; to be afraid. 

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