dirty work vs dissemblance

dirty work

noun
  • One or more unpleasant tasks, assignments, or employment duties, especially those of a disreputable or illicit nature. 

dissemblance

noun
  • An act of dissembling. 

  • Dissembling, as a kind of behavior; dissembling, generally. 

  • Dissimilarity, unlikeness. 

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