bulwark vs refuge

bulwark

noun
  • A defense or safeguard. 

  • A defensive wall or rampart. 

  • A breakwater. 

  • Any means of defence or security. 

  • The planking or plating along the sides of a nautical vessel above her gunwale that reduces the likelihood of seas washing over the gunwales and people being washed overboard. 

verb
  • To fortify something with a wall or rampart. 

  • To provide protection of defense for something. 

refuge

noun
  • An expedient to secure protection or defence. 

  • A state of safety, protection or shelter. 

  • A refuge island. 

  • A place providing safety, protection or shelter. 

  • Something or someone turned to for safety or assistance; a recourse or resort. 

verb
  • To return to a place of shelter. 

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