From SuspireWiki

(n., traditional)

Payment due to a lord in blood, traditionally in exchange for granted lands or titles. Blood rent may require a vassal to escort a lord on the hunt, to deliver a living vessel or to give up Vitae from the vassal’s own veins, depending on the contract of fealty between them. “I’ll give you everything between the expressway and Shadowgate Avenue, and in exchange you pay me a blood rent of one boy, no older than 19 and no younger than 14, for feeding, twice a month.”