from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An edible plant (Brassica rapa var. nipposinica) in the mustard family, having dark green, glossy, feathery leaves and white stems.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. One of several tangy green used in Japanese cuisine, usually Brassica rapa var. nipposinica
Japanese : mizu, water + na, mustard plant.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Japanese 水菜 (Wiktionary)