tremble vs whirlpool

tremble

verb
  • To shake, quiver, or vibrate. 

  • To fear; to be afraid. 

noun
  • A shake, quiver, or vibration. 

whirlpool

verb
  • To spin or swirl like the water in a whirlpool. 

noun
  • A swirling body of water. 

  • Turmoil, or agitated excitement. 

  • A hot tub, jacuzzi. 

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