habituation vs usance

habituation

noun
  • The act of habituating, or accustoming; the state of being habituated. 

  • The process of becoming accustomed to an internal or external stimulus, such as a noxious smell or loud noise. 

usance

noun
  • Customary or habitual usage. 

  • Use. 

  • The interest paid on a borrowed sum, usury. 

  • The length of time permitted for the payment of a bill of exchange. 

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