boil over vs plaw

boil over

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

  • To reach the point where aggressive action is taken. 

plaw

verb
  • To boil; seethe. 

  • To boil; boil slightly; parboil. 

noun
  • A boiling. 

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