head-on vs univocal

head-on

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

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

adv
  • With the front of a vehicle. 

  • With direct confrontation. 

noun
  • A collision from the front. 

univocal

adj
  • Unequivocal; indubitable. 

  • Containing instances of only one vowel; univocalic. 

  • Having unison of sound, as the octave has in music. 

  • Having only one possible meaning. 

  • Having always the same drift or tenor; uniform; certain; regular. 

noun
  • A document containing instances of only one vowel. 

  • A word having only one meaning. 

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