daikon

noun

1. An East Asian cultivar or subspecies of radish (Raphanus raphanistrum subsp. sativus, syn. Raphanus sativus) bearing a large, white, carrot-shaped taproot consumed throughout East and South Asia but grown in North America primarily as a fallow crop for its fast-growing leaves (used as animal fodder) and as a soil ripper.
2. Closely-related cultivars such as the enormous turnip-shaped Sakurajima or green-and-red watermelon radish.