noun
sword bean; Canavalia gladiata
A leguminous plant with large pods, often used in traditional medicine or as a food ingredient. The name comes from the pod's resemblance to a sword (鉈).
なた豆は健康茶の原料として使われることがあります。
Sword beans are sometimes used as an ingredient in health tea.
庭でなた豆を育てています。
I'm growing sword beans in my garden.
The name なたまめ (sword bean) comes from the shape of the pod, which resembles a 鉈 (nata, a type of hatchet or cleaver). The exact historical derivation is uncertain.