From WikiPilipinas: The Hip 'n Free Philippine Encyclopedia
In Philippine history, juramentado is an antiquated term that originated from the Spanish word juramentar meaning "one who takes an oath". It refers to a male Moro warrior who sacrificed his life in killing Christians. Governor General Jose Malcampo y Monje was first to employ such act during the final occupation of Jolo in 1876. The practice was originally conducted by a group of men who were willing to die just to accomplish their duty detailed in the Koran - that is, waging jihad or Holy War upon infidels and unbelievers.
Juramentado was the degraded form of jihad developed by the Sulu Moros.