head-on vs linear

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. 

linear

adj
  • Having the form of a line; straight or roughly straight; following a direct course. 

  • A type of length measurement involving only one spatial dimension (as opposed to area or volume). 

  • Long and narrow, with nearly parallel sides. 

  • Made, or designed to be used, in a step-by-step, sequential manner. 

  • Of or relating to a class of polynomial of the form y=ax+b. 

  • Of or relating to lines. 

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