Source : Webster's Revised Unabridged Dictionary (1913)

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}.

Source : WordNet®

peanut
     n 1: underground pod of the peanut vine
     2: widely cultivated American plant cultivated in tropical and
        warm regions; showy yellow flowers on stalks that bend
        over to the soil so that seed pods ripen underground [syn:
         {peanut vine}, {Arachis hypogaea}]
     3: a young child who is small for his age
     4: pod of the peanut vine containing usually 2 nuts or seeds;
        `groundnut' and `monkey nut' are British terms [syn: {earthnut},
         {goober}, {goober pea}, {groundnut}, {monkey nut}]

peanut
     adj : of little importance or influence or power; of minor status;
           "a minor, insignificant bureaucrat"; "peanut
           politicians" [syn: {insignificant}]