acquaintanceship vs cohabitation

acquaintanceship

noun
  • A relationship as acquaintances. 

  • The state of being acquainted. 

cohabitation

noun
  • The act of living together. 

  • A place where two or more individuals reside together. 

  • The act of two species living together in the same habitat. 

  • An emotional and physical intimate relationship which includes a common living place and which exists without legal or religious sanction. 

  • Cooperation between politicians of opposing political parties; especially, in France, between a President and Prime Minister. 

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