society > armed hostility > warrior > soldier > soldier by type of service > [noun] > irregular (11)
spec. Any one of a band of undisciplined camp followers or pillagers moving with, in advance of, or behind the main body of an army, and sometimes…
Military. A member of a small body of light or irregular troops operating independently and engaging in surprise attacks, etc.; a guerrilla. Also…
In extended use and figurative: any irregular soldier; a bandit, a rogue.