phlegmatic vs tranquil

phlegmatic

adj
  • Not easily excited to action or passion; calm; sluggish. 

  • Generating, causing, or full of phlegm. 

noun
  • One who has a phlegmatic disposition. 

tranquil

adj
  • Calm; without motion or sound. 

  • Free from emotional or mental disturbance. 

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