earthnut

noun

1. any of various roots, tubers, or underground growths, as the peanut and the truffle.
2. any of the plants producing these.

noun

1. Also called: pignut a perennial umbelliferous plant, Conopodium majus, of Europe and Asia, having edible dark brown tubers
2. any of various plants having an edible root, tuber, underground pod, or similar part, such as the peanut or truffle