The term legume has two closely related meanings in botany:
- The common name for plant species in the Family Fabaceae
- Legumes are noteworthy for their ability to fix atmospheric nitrogen, an accomplishment attributable to a symbiotic relationship with certain bacteria found in root nodules of these plants.
- The name of a type of fruit, characteristic of leguminous plants.
- A legume is a simple dry fruit that develops from a simple carpel and usually dehisces (opening along a seam) on two sides. A common name for this type of fruit is a "pod", although pod is also applied to a few other fruit types. Well-known plants that have legume fruits include alfalfa, clovers, peas, beans, and peanuts. A peanut is an indehiscent legume—that is, it does not spontaneously split open along a seam. A peanut is not a nut in the botanical use of the word.