boule vs rugby ball

boule

noun
  • One of the bowls used in the French game of boules. 

  • A single-crystal ingot produced by synthetic means. 

  • A round loaf of bread. 

  • A round piece of dough. 

  • A through-sawn log with the slices restacked in the order and orientation they originally had in the log, usually with waney edges. 

  • A council of citizens in Ancient Greece 

verb
  • To shape (a piece of dough) into a ball. 

rugby ball

noun
  • A spheroidal ball designed for the sport of rugby. 

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