irrational vs lethetic

irrational

adj
  • Not rational; unfounded or nonsensical. 

  • Of a real number, that cannot be written as the ratio of two integers. 

noun
  • A real number that can not be expressed as the quotient of two integers, an irrational number. 

lethetic

adj
  • Failing to mirror reality, purely escapist or nonsensical. 

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