head-on vs irrational

head-on

adj
  • Direct, abrupt, blunt or unequivocal; not prevaricating. 

  • Of a collision, from the front or in the direction of motion. 

noun
  • A collision from the front. 

adv
  • With the front of a vehicle. 

  • With direct confrontation. 

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. 

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