acquaintanceship vs prior knowledge

acquaintanceship

noun
  • The state of being acquainted. 

  • A relationship as acquaintances. 

prior knowledge

noun
  • Used other than figuratively or idiomatically: see prior, knowledge. 

  • Knowledge of a set of circumstances sufficient to make actions based on those circumstances wrongful. 

  • Prior to the inception of an insurance policy, knowledge of specific extant circumstances that could reasonably give rise to a claim under that policy. 

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