Term for those we call "mercenaries. The Low Countries were a principal recruiting area for these very cosmopolitan bands of soldiers. They were made up from outlaws, spoiled priests, and any unsuited to civilian life and wanting adventure. During the 12c these men pillaged and ravaged their way through the lands of their foes and nominal friends fairly indiscriminately. Often uncontrollable, typically when their paymaster was short of funds and unable to pay, they would plunder promiscuously. The Latin form is *ruptarius. -
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.