pretext vs trickery

pretext

noun
  • A false, contrived, or assumed purpose or reason; a pretense. 

verb
  • To employ a pretext, which involves using a false or contrived purpose for soliciting the gain of something else. 

trickery

noun
  • Deception or underhanded behavior. 

  • The art of dressing up; imposture. 

  • Artifice; the use of one or more stratagems. 

  • An instance of deception, underhanded behavior, dressing up, imposture, artifice, etc. 

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