Source : Webster's Revised Unabridged Dictionary (1913)

Truffle \Truf"fle\ (?; 277), n. [OF. trufle, F. truffe; akin to
   Sp. trufa, tartufo; of uncertain origin; perhaps from L.
   tuber a tumor, knob, truffle. Cf. {Tuber}, {Trifle}.]
   Any one of several kinds of roundish, subterranean fungi,
   usually of a blackish color. The French truffle ({Tuber
   melanosporum}) and the English truffle ({T. [ae]stivum}) are
   much esteemed as articles of food.

   {Truffle worm} (Zo["o]l.), the larva of a fly of the genus
      {Leiodes}, injurious to truffles.

Source : WordNet®

truffle
     n 1: any of various highly prized edible subterranean fungi of
          the genus Tuber; grow naturally in southwestern Europe
          [syn: {earthnut}, {earth-ball}]
     2: edible subterranean fungus of the genus Tuber [syn: {earthnut}]
     3: creamy chocolate candy [syn: {chocolate truffle}]