Webster's Revised Unabridged Dictionary · 1913

Peanut

Peanut (pē"nut) , noun

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

The fruit is a hard pod, usually containing two or three seeds, sometimes but one, which ripen beneath the soil. Called also earthnut, groundnut, and goober.