cave in vs enlarge

cave in

verb
  • To relent; to grant approval against one's initial will. 

  • To collapse inward or downward. 

noun
  • The act of relenting. 

  • The location where something has caved in. 

  • The act of something collapsing or caving in. 

enlarge

verb
  • To extend the time allowed for compliance with (an order or rule). 

  • To increase the capacity of; to expand; to give free scope or greater scope to; also, to dilate, as with joy, affection, etc. 

  • To speak or write at length upon or on (some subject); expand; elaborate 

  • To get more astern or parallel with the vessel's course; to draw aft; said of the wind. 

  • To make (something) larger. 

  • To grow larger. 

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