bailey vs breastwork

bailey

noun
  • The outer wall of a feudal castle. 

  • A prison or court of justice. 

  • The space immediately within the outer wall of a castle or fortress. 

breastwork

noun
  • A fortification consisting of a breast-high bulwark; a parapet. 

  • A parapet. 

  • Breast augmentation. 

  • A railing on the quarter-deck and forecastle. 

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