caesura vs discontinuity

caesura

noun
  • A break of an era or other measure of history and time; where one era ends and another begins; turning point. 

  • Using two words to divide a metrical foot. 

  • A pause or interruption in a poem, music, building, or other work of art. 

  • The caesura mark ‖ or ||. 

discontinuity

noun
  • A lack of continuity, regularity or sequence; a break or gap. 

  • a subterranean interface at which seismic velocities change 

  • A point in the range of a function at which it is undefined or discontinuous. 

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