irregular warfare noun2 •Warfare in which one or more combatants are irregulars (such as partisans, guerrillas or insurgents) rather than regular military forces.Studying the raid's effect on one community reveals how the different forms of irregular warfare — partisan warfare, guerrilla tactics, and cavalry raids — intertwined along the Ohio River border. — 2010 •Warfare with the aim of gaining or establishing political authority using asymmetric warfare tactics.