a member of a small independent fighting force which engages in sabotage, unexpected assaults, etc, usu with a political objective
Spanish guerrilla, dimin. of guerra war, of Germanic origin. This word entered English from Spanish during the Peninsular War fought in Spain and Portugal from 1808 to 1814; its first recorded use appears in the writings of the Duke of Wellington, commander of the British forces. It was originally applied to Spanish and Portuguese groups who harassed the French troops and played a significant role in expelling them from the Peninsula