Source : Webster's Revised Unabridged Dictionary (1913)

Tuber \Tu"ber\, n.[L., a hump. knob; probably akin to tumere to
   swell. Cf. {Tumid}.]
   1. (Bot.)
      (a) A fleshy, rounded stem or root, usually containing
          starchy matter, as the potato or arrowroot; a
          thickened root-stock. See Illust. of {Tuberous}.
      (b) A genus of fungi. See {Truffle}.

   2. (Anat.) A tuberosity; a tubercle.

Source : WordNet®

tuber
     n 1: a fleshy underground stem or root serving for reproductive
          and food storage
     2: type genus of the Tuberaceae: fungi whose fruiting bodies
        are typically truffles [syn: {genus Tuber}]