guerrilla A Spanish term meaning ‘little war’, universally applied to low-level or irregular warfare, using social, political, and geographical advantages against conventionally superior forces. It is often associated with resistance by peasants, and was developed as a form of revolutionary and anti-colonial movement in the post-1945 period, based on the theories of guerrilla warfare propounded by Mao Zedong and Che Guevara. The idea is much romanticized but has had some practical successes.

guer·ril·la / gəˈrilə/ (also gue·ril·la) • n. a member of a small independent group taking part in irregular fighting, typically against larger regular forces: this small town fell to the guerrillas | [as adj.] guerrilla warfare.