incommensurable vs unmatchable

incommensurable

adj
  • Not able to be measured by the same standards as another term in the context. 

  • having a ratio that is not expressible as a fraction of two integers. 

  • having no common integer divisor except 1. 

noun
  • An incommensurable value or quantity; an irrational number. 

unmatchable

adj
  • Unable to be matched. 

  • Uniquely good; not approached by anything else in quality or excellence. 

noun
  • Something that cannot be matched. 

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