蒟蒻, 菎蒻: konjac (both the plant and the food made from the plant) · short for 蒟蒻島 (Konnyaku-jima): obsolete name for the 新川 (Shingawa) area in modern-day 中央区 (Chūō-ku, “Central Ward”) in Tokyo
köken: Probably from Old Japanese, in turn from Middle Chinese 蒟蒻 (MC kjuX nyak). The plant is not native to the Japanese archipelago, and was imported from China. First cited to the 本草和名 (Honsō Wamyō) of circa 918 CE with the reading konyaku. The geminate reading konnyaku is first cited to a text from 1336.