rondure vs rounding

rondure

noun
  • A graceful curvature or round object; a ring; a sphere. 

  • The quality of being round; roundness. 

rounding

noun
  • A rounded surface; a curve. 

  • The numerical value obtained by this process. 

  • The act by which a numerical value is rounded. 

  • In bookbinding, the shaping of the folded and sewed sheets into a convex form at the back. 

  • The act of making anything round, as the lips in pronouncing some vowels. 

adj
  • Round or nearly round; becoming round; roundish. 

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