dummy up vs open up

dummy up

verb
  • To make a mock-up or prototype version of something, without some or all off its intended functionality. 

  • To suddenly stop talking; shut up. 

open up

verb
  • 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. 

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

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