primal vs undergo

primal

verb
  • To take part in primal therapy. 

adj
  • Being the first in time or in history. 

  • Of greatest importance; primary. 

  • Being one of the pieces of meat initially separated from the carcass during butchering, prior to division into smaller cuts. 

noun
  • A primal cut (of meat). 

undergo

verb
  • To experience; to pass through a phase. 

  • The project is undergoing great changes. 

  • To suffer or endure; bear with. 

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