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.adjectivePertaining to tension, especially of muscles.
6.adjectiveRestorative, curative or invigorating."The arrival of the new members had a tonic effect on the team."