assurance vs doubt

assurance

noun
  • The state of being assured; total confidence or trust; a lack of doubt; certainty. 

  • Subjective certainty of one's salvation. 

  • The act of assuring; a declaration tending to inspire full confidence; something designed to give confidence. 

  • Firmness of mind; undoubting steadiness; intrepidity; courage; confidence; self-reliance. 

  • Insurance; a contract for the payment of a sum on occasion of a certain event, as loss or death. Assurance is used in relation to life contingencies, and insurance in relation to other contingencies. It is called temporary assurance, in the time within which the contingent event must happen is limited. 

  • Excessive boldness; impudence; audacity 

  • Any written or other legal evidence of the conveyance of property; a conveyance; a deed. 

doubt

noun
  • Disbelief or uncertainty (about something); (countable) a particular instance of such disbelief or uncertainty. 

verb
  • To be undecided about; to lack confidence in; to disbelieve, to question. 

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