The Collaborative International Dictionary of English v.0.48:

Cardigan \Car"di*gan\, Cardigan jacket \Car"di*gan jack`et\
   [From the Earl of Cardigan, who was famous in the Crimean
   campaign of 1854-55.]
   1. A warm jacket of knit worsted with or without sleeves,
      especially a knitted jacket with sleeves that is fastened
      up the front with buttons or a zipper.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cardigan \Car"di*gan\,
   a slightly bow-legged variety of corgi having rounded ears
   and a long tail.

   Syn: Cardigan Welsh corgi.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

cardigan
    n 1: knitted jacket that is fastened up the front with buttons
         or a zipper
    2: slightly bowlegged variety of corgi having rounded ears and a
       long tail [syn: Cardigan, Cardigan Welsh corgi]