Gin is a juniper berry-flavored grain spirit . The word is an English shortening of Genever, the Dutch word for juniper.
The best known of these cocktails, the Gin and Tonic, was created as a way for Englishmen in tropical colonies to take their daily dose of quinine, a very bitter medicine used to ward off malaria. Modern tonic water still contains quinine, though as a flavoring rather than a medicine.