Definitions
1.nounA substance with medicinal properties intended to restore or invigorate."We used to brew a tonic from a particular kind of root."
2.nounTonic water.
3.noun(Massachusetts) Any of various carbonated, non-alcoholic beverages; soda pop.
4.nounSomeone or something that revitalises or reinvigorates.
5.nounThe first note of a diatonic scale; the keynote.
6.nounThe triad built on the tonic note.
7.nounA tonic element or letter; a vowel or a diphthong.