The disarming spell (incantation: carpo) is a spell that, when cast on a held item, causes it to fly away from someone's hand. It is usually used on a weapon, such as a wand.
The incantation carpo is Latin and means a variety of things: "pluck, pick, harvest", "tear off, tear out, rend", "seize, utilize" and more, but for the spell, the meanings associated with taking away applies. Etymologically it is derived from Proto-Italic *karpō, from Proto-Indo-Eurooean *kerp-. Compare Greek καρπός (karpós, “fruit”) and κείρω (keírō, “to cut off”), English harvest, sharp, shear.