serene vs undisturbed

serene

adj
  • Calm, peaceful, unruffled. 

  • Without worry or anxiety; unaffected by disturbance. 

  • Used as part of certain titles, originally to indicate sovereignty or independence. 

noun
  • Serenity; clearness; calmness. 

  • A fine rain from a cloudless sky after sunset. 

verb
  • To make serene. 

undisturbed

adj
  • calm 

  • not disturbed or agitated 

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