flip side vs privative

flip side

noun
  • The converse; opposite, usually negative, inherent aspects or consequences of something. 

  • The reverse, in contrast to the obverse. 

privative

noun
  • something that causes privation or indicates an absence 

adj
  • causing privation; depriving 

  • consisting in the absence of something; negative 

  • indicating the absence of something 

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