The Collaborative International Dictionary of English v.0.48:

Polenta \Po*len"ta\, n. [It., fr. L. polenta peeled barley.]
   Pudding made of Indian meal; also, porridge made of chestnut
   meal. [Italy]
   [1913 Webster]

WordNet (r) 3.0 (2006):

polenta
    n 1: a thick mush made of cornmeal boiled in stock or water