groundnut

UK: /ˈgraʊndnʌt/ US: /ˈgraʊndˌnʌt/ ,(ground′nut′)

WordReference Random House Learner's Dictionary of American English © 2025

ground•nut /ˈgraʊndˌnʌt/  n. [countable]

1. a peanut.

WordReference Random House Unabridged Dictionary of American English © 2025

ground•nut  (ground′nut′), n. 

1. Plant Biology Also called wild bean, potato bean. a twining, North American plant, Apios americana (or A. tuberosa), of the legume family, having clusters of fragrant brownish flowers and an edible tuber.
2. Plant Biology any of several other plants having edible underground parts, as the peanut.
3. Plant Biology, Dialect Terms [South Atlantic U.S.] peanut.

• ground¹ + nut 1595–1605

Collins Concise English Dictionary © HarperCollins Publishers::

groundnut / ˈɡraʊndˌnʌt/ noun

1. a North American climbing leguminous plant, Apios tuberosa, with fragrant brown flowers and small edible underground tubers
2. the tuber of this plant
3. 
   another name for peanut