defense vs fortification

defense

noun
  • The action of defending or protecting from attack, danger, or injury. 

  • Government policy or (infra)structure related to the military. 

  • A strategy and tactics employed to prevent the other team from scoring; contrasted with offense. 

  • The case presented by the defendant in a legal proceeding. 

  • The lawyer or team thereof who presents such a case. 

  • The portion of a team dedicated to preventing the other team from scoring; contrasted with offense. 

fortification

noun
  • The act of fortifying; the art or science of fortifying places to strengthen defence against an enemy. 

  • A jagged pattern sometimes seen during an attack of migraine. 

  • That which fortifies; especially, a work or works erected to defend a place against attack; a fortified place; a fortress; a fort; a castle. 

  • An increase in effectiveness, as by adding ingredients. 

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