GROUNDNUT
peanut, earthnut, goober, goober pea, groundnut, monkey nut
(noun) pod of the peanut vine containing usually 2 nuts or seeds; ‘groundnut’ and ‘monkey nut’ are British terms
groundnut, potato bean, wild bean
(noun) nutlike tuber; important food of Native Americans
groundnut, groundnut vine, Indian potato, potato bean, wild bean, Apios americana, Apios tuberosa
(noun) a North American vine with fragrant blossoms and edible tubers; important food crop of Native Americans
Source: WordNet® 3.1
Etymology
Noun
groundnut (plural groundnuts)
A climbing vine, Apios americana, of eastern North America, having fragrant brownish flowers and small edible tubers.
Any similar plant having underground tubers.
The nutlike tuber of such a plant, especially peanuts.
A plant which bears its nutlike seeds underground, such as a peanut or Bambara groundnut.
Source: Wiktionary
Ground"nut`, n. (Bot.)
(a) The fruit of the Arachis hypogæa (native country uncertain); the
peanut; the earthnut.
(b) A leguminous, twining plant (Apios tuberosa), producing clusters
of dark purple flowers and having a root tuberous and pleasant to the
taste.
(c) The dwarf ginseng (Aralia trifolia). [U. S.] Gray.
(d) A European plant of the genus Bunium (B. flexuosum) having an
edible root of a globular shape aud sweet, aromatic taste; -- called
also earthnut, earth chestnut, hawknut, and pignut.
Source: Webster’s Unabridged Dictionary 1913 Edition