head-on vs proximate

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. 

proximate

adj
  • Immediately preceding or following in a chain of causation. 

  • Close or closest; adjacent. 

  • About to take place; impending. 

noun
  • A grammatical marker that distinguishes a relatively salient referent in a given context from a relatively non-salient (obviative) one. 

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