绿豆 (lǜdòu) literally means 'green bean' — 绿 (lǜ) means 'green', and 豆 (dòu) means 'bean'. It refers specifically to the small, round, green legume known in English as the mung bean, widely used in East and Southeast Asian cuisines. Unlike the green beans commonly eaten in Western countries (which are immature pods of Phaseolus vulgaris), 绿豆 is a seed bean, typically dried and split, with a mild, slightly sweet flavor and soft texture when cooked.

This ingredient is especially valued in traditional Chinese medicine for its cooling properties and is often used in summer soups, desserts like mung bean paste or jelly, and detoxifying broths. It’s also ground into flour for noodles or pancakes. The word is neutral in register and appears frequently in cooking, health, and grocery contexts — never used metaphorically or idiomatically.