arrowroot: [17] Arrowroot, a tropical American plant with starchy tubers, gets its name by folk etymology, the process whereby an unfamiliar foreign word is reformulated along lines more accessible to the speakers of a language. In this case the word in question was aru-aru, the term used by the Arawak Indians of South America for the plant (meaning literally ‘meal of meals’). English-speakers adapted this to arrowroot because the root of the plant was used by the Indians to heal wounds caused by poisoned arrows. [arrowroot etymology, arrowroot origin, 英语词源]