discordance vs lack of similarity

discordance

noun
  • The presence of a specific genetic trait in only one of a set of clones (or identical twins). 

  • Discordance of sounds; dissonance. 

  • A state of being discordant; disagreement, inconsistency. 

lack of similarity

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