assurance vs flap

assurance

noun
  • Excessive boldness; impudence; audacity 

  • 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. 

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

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

flap

noun
  • A controversy, scandal, stir, or upset. 

  • A side fin of a ray. 

  • A consonant sound made by a single muscle contraction, such as the sound /ɾ/ in the standard American English pronunciation of body. 

  • The motion of anything broad and loose, or a sound or stroke made with it. 

  • Anything broad and flexible that hangs loose, or that is attached by one side or end and is easily moved. 

  • A piece of tissue incompletely detached from the body, as an intermediate stage of plastic surgery. 

  • A hinged leaf. 

  • The labia, the vulva. 

  • A hinged surface on the trailing edge of the wings of an aeroplane, used to increase lift and drag. 

verb
  • To move loosely back and forth. 

  • To move (something broad and loose) up and down. 

  • Of a resource or network destination: to be advertised as being available and then unavailable (or available by different routes) in rapid succession. 

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