A substance with medicinal properties intended to restore or invigorate.

“We used to brew a tonic from a particular kind of root.”

Tonic water.

(Massachusetts) Any of various carbonated, non-alcoholic beverages; soda pop.

Pertaining to tension, especially of muscles.

Restorative, curative or invigorating.

“The arrival of the new members had a tonic effect on the team.”