The Collaborative International Dictionary of English v.0.48:

Bourbon \Bour"bon\, n. [From the castle and seigniory of Bourbon
   in central France.]
   [1913 Webster]
   1. A member of a family which has occupied several European
      thrones, and whose descendants still claim the throne of
      France.
      [1913 Webster]

   2. A politician who is behind the age; a ruler or politician
      who neither forgets nor learns anything; an obstinate
      conservative.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Bourbon
    n 1: a reactionary politician in the United States (usually from
         the South)
    2: whiskey distilled from a mash of corn and malt and rye and
       aged in charred oak barrels
    3: a member of the European royal family that ruled France
    4: a European royal line that ruled in France (from 1589-1793)
       and Spain and Naples and Sicily [syn: Bourbon, Bourbon
       dynasty]