bulwark vs yield

bulwark

verb
  • To provide protection of defense for something. 

  • To fortify something with a wall or rampart. 

noun
  • A defensive wall or rampart. 

  • A defense or safeguard. 

  • 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. 

yield

verb
  • To give as required; to surrender, relinquish or capitulate. 

  • To furnish; to afford; to render; to give forth. 

  • To produce as a result. 

  • To give, or give forth, (anything). 

  • To produce a particular sound as the result of a sound law. 

  • To produce as return, as from an investment. 

  • To give way; to succumb to a force. 

  • To pass the material's yield point and undergo plastic deformation. 

  • To admit to be true; to concede; to allow. 

  • To give way; to allow another to pass first. 

noun
  • Profit earned from an investment; return on investment. 

  • A product; the quantity of something produced. 

  • The explosive energy value of a bomb, especially a nuke, usually expressed in tons of TNT equivalent. 

  • The current return as a percentage of the price of a stock or bond. 

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