一切經音義 46.363

46.363

級其（羇立反級次也謂階之筭數名曰級師族斬𩠐一人賜爵一級因名賊𩠐為級也）。

級其 "Rank/decapitated head" (fanqie: 羇立 [jī]). A 'level' (級) is an order/tier; it refers to the calculated number of steps, which is called a 'grade' or 'tier' (級). When an army decapitated one person's head, they were bestowed one grade of aristocratic rank; hence the head of an enemy came to be called a ji (級).