The Collaborative International Dictionary of English v.0.48:

Gin \Gin\ (j[i^]n), n. [Contr. from Geneva. See 2d Geneva.]
   A strong alcoholic liquor, distilled from rye and barley, and
   flavored with juniper berries; -- also called Hollands and
   Holland gin, because originally, and still very
   extensively, manufactured in Holland. Common gin is usually
   flavored with turpentine.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Holland gin
    n 1: gin made in the Netherlands [syn: geneva, Holland gin,
         Hollands]