1.
bean sprouts
Young sprouted beans, most commonly mung bean sprouts. A staple inexpensive vegetable in Japanese cooking.
Writing
Usually written in hiragana. The kanji 萌し exists but is not commonly used.
Cultural note
One of the cheapest vegetables available at Japanese supermarkets, often used in stir-fries, ramen, and namul. Known as a go-to ingredient for budget cooking.
Common collocations
Slang
もやしっ子 refers to a weak, skinny person (like a bean sprout).