XEARTH'NUT, n. The groundnut, or root of the Arachis; a small round bulb or knob, like a nut. This root or bulb is formed from the germen, which becomes a pod and is thrust into the ground by a natural motion of the stalk.

It is properly the fruit of the plant, and differs from other fruit only in the circumstance of ripening in the earth.

, n. The pignut, or bunium; a globular root, somewhat resembling in taste a chestnut, whence it is called bulbocastanum.