defense vs invasion

defense

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

  • 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. 

invasion

noun
  • A military action consisting of armed forces of one geopolitical entity entering territory controlled by another such entity, generally with the objective of conquering territory or altering the established government. 

  • The breaching of the skin barrier. 

  • The spread of cancer cells, bacteries and such to the organism. 

  • The entry without consent of an individual or group into an area where they are not wanted. 

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