TONIC

I. adjective Etymology: Greek tonikos, from tonos tension, tone Date: 1649 1. characterized by tonus , producing or adapted to produce healthy muscular condition and reaction of organs (as muscles), 2. increasing or restoring physical or mental tone ; refreshing , yielding a ~ substance, relating to or based on the first tone of a scale , bearing a principal stress or accent, of or relating to speech tones or to languages using them to distinguish words otherwise identical, ~ally adverb II. noun Date: 1797 the first tone of a major or minor scale ; keynote , 2. an agent (as a drug) that increases body tone, one that invigorates, restores, refreshes, or stimulates , a liquid preparation for the scalp or hair, a carbonated flavored beverage, ~ water , a voiced sound