boak vs regurge

boak

verb
  • To retch or vomit. 

regurge

verb
  • To throw up or vomit; to eject what has previously been swallowed. 

noun
  • Regurgitation, resurging or reflux (of something, e.g. a fluid, through a suture, a valve, etc). 

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