head-on vs volatile

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. 

volatile

adj
  • Temporary or ephemeral. 

  • Explosive. 

  • Variable or erratic. 

  • Quick to become angry or violent. 

  • Fickle. 

  • Whose content is lost when the computer is powered down 

  • Having its associated memory immediately updated with any changes in value. 

  • Potentially violent. 

  • Evaporating or vaporizing readily under normal conditions. 

noun
  • A variable that is volatile, i.e. has its associated memory immediately updated with any change in value. 

  • A chemical or compound that changes into a gas easily. 

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