confound vs open up

confound

verb
  • To fail to see the difference; to mix up; to confuse right and wrong. 

  • To combine in a confused fashion; to mingle so as to make the parts indistinguishable. 

  • To stun or amaze. 

  • To make something worse. 

  • To cause to be ashamed; to abash. 

  • To defeat, to frustrate, to thwart. 

  • To perplex or puzzle. 

noun
  • A confounding variable. 

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 confound and open up occurred in a corpus of books? (source: Google Ngram Viewer )