head-on vs prominent

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. 

prominent

adj
  • standing out, or projecting; jutting; protuberant 

  • likely to attract attention from its size or position; conspicuous 

  • eminent; distinguished above others 

noun
  • Any of various moths having a conspicuous projection on the inner margin of the wings. 

  • In Nazi concentration camps, an inmate entrusted with minor supervisory duties and rewarded with perquisites. 

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