What is "arachis hypogaea"

Groundnut \Ground"nut`\ (ground"n[u^]t`), n. (Bot.)

1. The fruit of the Arachis hypog[ae]a (native country uncertain); the peanut; the earthnut.

2. A leguminous, twining plant ( Apios tuberosa), producing clusters of dark purple flowers and having a root tuberous and pleasant to the taste.

3. The dwarf ginseng ( Aralia trifolia). [U. S.]
   --Gray.

4. A European plant of the genus Bunium ( B. flexuosum), having an edible root of a globular shape and sweet, aromatic taste; -- called also earthnut, earth chestnut, hawknut, and pignut.

Peanut \Pea"nut\, n. (Bot.) The fruit of a trailing leguminous plant ( Arachis hypog[ae]a); also, the plant itself, which is widely cultivated for its fruit.

Note: 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.

Pindal \Pin"dal\, Pindar \Pin"dar\, n. [D. piendel.] (Bot.) The peanut ( Arachis hypog[ae]a); -- so called in the West Indies.

Hypogaeic \Hyp`o*g[ae]"ic\, a. [Pref. hypo- + Gr. gai^a, gh^, earth.] (Chem.) Pertaining to, or obtained from, the peanut, or earthnut ( Arachis hypog[ae]a).

Hypog[ae]ic acid (Chem.), an acid in the oil of the earthnut, in which it exists as a glyceride, and from which it is extracted as a white, crystalline substance.