The Collaborative International Dictionary of English v.0.48:

Dixie \Dix"ie\ (d[i^]ks"[y^]), prop. n.
   1. A colloquial name for the Southern portion of the United
      States, esp. during the Civil War. [U.S.]

   Syn: Dixieland, Dixie Land, the Confederacy, Confederate
        States of America, the South.

   Syn: . [1913 Webster]

   2. a song popular in the Confederate states during the
      American Civil War, and still played as a nostalgic anthem
      by those patriotic to the American south. It was written
      by Daniel D. Emmett in 1859.
      [PJC]

   whistle Dixie to talk unrealistically; to engage in
      unrealistic or overoptimistic fantasies; as, that ain't
      just whistlin' Dixie.
      [PJC]

WordNet (r) 3.0 (2006):

Dixie
    n 1: the southern states that seceded from the United States in
         1861 [syn: Confederacy, Confederate States,
         Confederate States of America, South, Dixie,
         Dixieland]
    2: a large metal pot (12 gallon camp kettle) for cooking; used
       in military camps