peanut

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A prostrate southern Brazilian plant (Arachis hypogaea) widely cultivated in tropical and warm temperate regions, having yellow flowers on stalks that bend over so that the seed pods ripen underground.
2. n. The edible, nutlike, oily seed of this plant, used for food and as a source of oil. Also called regionally goober, goober pea.
3. n. A peanut-shaped piece of polystyrene, used in cushioning items during shipment.
4. n. Slang A person small in stature.
5. n. Slang A person who is regarded as being insignificant.
6. n. Informal A very small amount of money; a trifling sum.
7. adj. Slang Having little or no importance; insignificant: peanut politicians.

Century Dictionary and Cyclopedia

1. n. One of the edible fruits of Arachis hypogæn.
2. n. The plant that bears these fruits, better known in England as groundnut. See Arachis. Also called ground-pea, earthnut, Manila nut, jur-nut, goober, and pindar.

Wiktionary

1. n. A legume resembling a nut, the fruit of the plant Arachis hypogaea.

GNU Webster's 1913

1. n. The fruit of a trailing leguminous plant (Arachis hypogæa); also, the plant itself, which is widely cultivated for its fruit.

WordNet 3.0

1. n. pod of the peanut vine containing usually 2 nuts or seeds; `groundnut' and `monkey nut' are British terms
2. n. widely cultivated American plant cultivated in tropical and warm regions; showy yellow flowers on stalks that bend over to the soil so that seed pods ripen underground
3. n. a young child who is small for his age
4. n. underground pod of the peanut vine
5. adj. of little importance or influence or power; of minor status