disuse vs tergiversation

disuse

noun
  • The state of not being used; neglect. 

verb
  • To cease the use of. 

tergiversation

noun
  • The act of evading any clear course of action or speech, of being deliberately ambiguous; equivocation; fickleness. 

  • The act of abandoning something or someone, of changing sides; desertion; betrayal. 

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