tonic

A drink that supposedly can make you stronger.

Example: Ben wanted bigger muscles, so he drank a glass of Beauregard's strength tonic

Tonic water, a drink made with quinine that is used in cocktails

Example: Devon went to the bar and ordered a gin and tonic

The keynote of a song (the note that says what other notes will be sharp or flat)

Pertaining to the keynote of a song