disquiet vs reassurance

disquiet

noun
  • Lack of quiet; absence of tranquility in body or mind 

verb
  • To make (someone or something) worried or anxious. 

reassurance

noun
  • The act of confirming someone's opinion or impression. 

  • Reinsurance. 

  • The feeling of being reassured, of having confidence restored, of having apprehensions dispelled. 

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