Definitions for tonic water
Random House Webster's College Dictionary
carbonated water containing lemon, sweetener, and quinine, used as a mixer.
Category: Common Vocabulary, Cooking
Ref: Also called tonic, 1 3 quinine water.
tonic, tonic water, quinine water(noun)
lime- or lemon-flavored carbonated water containing quinine
A carbonated beverage containing quinine, which is a medicine. It is used to make gin and tonic, a primarily recreational drink.