The Collaborative International Dictionary of English v.0.48:

Sauerkraut \Sauer"kraut`\, n. [G., fr. sauer sour + kraut herb,
   cabbage.]
   Cabbage cut fine and allowed to ferment in a brine made of
   its own juice with salt, -- a German dish.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sauerkraut
    n 1: shredded cabbage fermented in brine