quirky vs unrepeatable

quirky

adj
  • Given to quirks or idiosyncrasies; strange in a somewhat silly, awkward manner, potentially cute. 

unrepeatable

adj
  • (of an experiment or procedure) That gives different results when repeated 

  • Unable to be repeated 

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