purism vs tergiversation

purism

noun
  • An example of purist language etc. 

  • The desire to use words and forms derived from what is considered the native element in a given language instead of elements considered borrowed or foreign. 

  • An insistence on the traditionally correct way of doing things. 

  • An insistence on pure or unmixed forms. 

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 purism and tergiversation occurred in a corpus of books? (source: Google Ngram Viewer )