combatant vs guerrilla warfare

combatant

noun
  • A person engaged in combat, often armed. 

adj
  • Involving combat. 

  • Contending; disposed to contend. 

guerrilla warfare

noun
  • Combat using groups of irregular, light, mobile troops within areas occupied by an enemy force, usually through hit-and-run tactics. 

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