legume

noun

1. any of an order (Fabales) of dicotyledonous herbs, shrubs, and trees, including the peas, beans, mimosas, and the Kentucky coffee tree, with usually compound leaves, flowers having a single carpel, and fruit that is a dry pod splitting along two sutures: many legumes are nitrogen-fixing and often are used as green manure and for forage
2. the pod or seed of some members of this order, used for food