A prisoner's word of honour. Knights and magnates were expected to abide by their parole when captured and not try to escape. Under these terms a prisoner was allowed great freedom. It would not be chivalrous to break parole for that was breaking one's word - a great fault of honour. There was also a kind of bond here between equals, even if opponents in war. Indeed, the kinship appeared in their capturing each other, not killing each other. A captured knight, *baron or king, indeed, could be ransomed; a dead knight, baron or king was worthless. [< OldFr. parole = something said.]
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.