The Collaborative International Dictionary of English v.0.48:

Aguardiente \A`guar*di*en"te\, n. [Sp., contr. of agua ardiente
   burning water (L. aqua water + ardens burning).]
   1. A inferior brandy of Spain and Portugal.
      [1913 Webster]

   2. A strong alcoholic drink, especially pulque. [Mexico and
      Spanish America.]
      [1913 Webster]