Source : Webster's Revised Unabridged Dictionary (1913)

Oca \O"ca\, n. [Sp.] (Bot.)
   A Peruvian name for certain species of Oxalis ({O. crenata},
   and {O. tuberosa}) which bear edible tubers.

Source : WordNet®

oca
     n : South American wood sorrel cultivated for its edible tubers
         [syn: {oka}, {Oxalis tuberosa}, {Oxalis crenata}]