The Collaborative International Dictionary of English v.0.48:

Fandango \Fan*dan"go\, n.; pl. Fandangoes. [Sp. A name
   brought, together with the dance, from the West Indies to
   Spain.]
   1. A lively dance, in 3-8 or 6-8 time, much practiced in
      Spain and Spanish America. Also, the tune to which it is
      danced.
      [1913 Webster]

   2. A ball or general dance, as in Mexico. [Colloq.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

fandango
    n 1: a provocative Spanish courtship dance in triple time;
         performed by a man and a woman playing castanets