caesura vs virgule

caesura

noun
  • 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 ||. 

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

virgule

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