gen up vs open up

gen up

verb
  • To study in detail; to familiarize oneself with all available information. 

  • To inform or teach with all relevant details; to brief. 

open up

verb
  • To reveal oneself; to share personal information about oneself; to become communicative. 

  • Synonym of cheat out (“to face or turn toward the audience more than would be natural”) 

  • To begin running, driving, travelling, etc., at maximum speed. 

  • To commence firing weapons. 

  • To rain. 

  • To open. 

  • To widen. 

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