head-on vs radiant

head-on

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

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

adv
  • With the front of a vehicle. 

  • With direct confrontation. 

noun
  • A collision from the front. 

radiant

adj
  • Emitting or proceeding as if from a center. 

  • Emitted as radiation. 

  • Radiating light and/or heat. 

  • Strikingly beautiful. 

  • Giving off rays; said of a bearing. 

  • Having a ray-like appearance, like the large marginal flowers of certain umbelliferous plants; said also of the cluster which has such marginal flowers. 

  • Beaming with vivacity and happiness. 

noun
  • The apparent origin, in the night sky, of a meteor shower. 

  • A point source from which radiation is emitted. 

  • A straight line proceeding from a given point, or fixed pole, about which it is conceived to revolve. 

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