/ Dictionary / Index T tonic water: Meaning and Definition of Find definitions for: ton'ic wa"ter. Pronunciation: [key] See quinine water. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. tonic spasm tonight Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language