The Collaborative International Dictionary of English v.0.48:

Champagne \Cham*pagne"\, n. [F. See Champaign.]
   A light wine, of several kinds, originally made in the
   province of Champagne, in France.
   [1913 Webster]

   Note: Champagne properly includes several kinds not only of
         sparkling but of still wines; but in America the term
         is usually restricted to wines which effervesce.
         [1913 Webster]

WordNet (r) 3.0 (2006):

champagne
    n 1: a white sparkling wine either produced in Champagne or
         resembling that produced there [syn: champagne, bubbly]
    2: a region of northeastern France [syn: Champagne,
       Champagne-Ardenne]