Source : Webster's Revised Unabridged Dictionary (1913)

Earthnut \Earth"nut`\, n. (Bot.)
   A name given to various roots, tubers, or pods grown under or
   on the ground; as to:
   (a) The esculent tubers of the umbelliferous plants {Bunium
       flexuosum} and {Carum Bulbocastanum}.
   (b) The peanut. See {Peanut}.