exceptional vs indistinguishable

exceptional

adj
  • Forming an exception; not ordinary; uncommon; rare. 

  • Corresponding to something of lower dimension under a birational correspondence. 

  • Better than the average; superior due to exception or rarity. 

noun
  • An exception, or something having an exceptional value 

indistinguishable

adj
  • Not distinguishable; not capable of being perceived, known, or discriminated as separate and distinct 

  • Not capable of being perceived or known. 

noun
  • Any of a set of things that cannot be distinguished. 

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