boil over vs overswell

boil over

verb
  • To boil to such an extent as to overflow its container. 

  • To reach the point where aggressive action is taken. 

overswell

verb
  • To swell or rise above (something, especially the rim of a container, the sides of something hollow, etc.). 

  • To cause (something) to be too swollen or large; to become too swollen or large. 

noun
  • An excessive or sudden increase or flood (of something). 

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