certainty vs semblance

certainty

noun
  • The state of being certain. 

  • A fact or truth unquestionably established. 

  • An instance of being certain. 

semblance

noun
  • likeness, similarity; the quality of being similar. 

  • the way something looks; appearance; form 

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