bombardment vs crossfire

bombardment

noun
  • heavy artillery fire 

  • the act of bombing, especially towns or cities 

  • the incidence of an intense stream of high-energy particles directed at a substance 

crossfire

noun
  • Lines of fire from multiple positions that cross in a small region 

  • A heated confrontation between opposing factions. 

How often have the words bombardment and crossfire occurred in a corpus of books? (source: Google Ngram Viewer )