frigidity vs restraint

frigidity

noun
  • Coldness of feeling, manner or quality; lack of ardor, animation or vivacity. 

  • The state of being frigid; coldness; lack of heat. 

  • Lack of natural heat and vigor of body; impotency. 

restraint

noun
  • something that restrains, ties, fastens or secures 

  • control or caution; reserve 

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