1. A medicine that strengthens and invigorates
   "The elderly man took a daily tonic to boost his energy levels";
   - restorative
    
2. A sweet drink containing carbonated water and flavouring
   "He mixed the gin with tonic water";
   - pop [N. Amer], soda, soda pop [N. Amer], soda water
    
3. Lime- or lemon-flavoured carbonated water containing quinine
   "He mixed gin with tonic water for a classic cocktail";
   - tonic water, quinine water
    
4. (music) the first note of a diatonic scale
   "The piece ended with a return to the tonic";
   - keynote

1. Imparting vitality and energy
   "the tonic mountain air";
   - bracing, brisk, fresh, refreshing, refreshful
    
2. (physiology) of or relating to or producing normal tone or tonus in muscles or tissue
   "a tonic reflex"; "tonic muscle contraction"
    
3. Employing variations in pitch to distinguish meanings of otherwise similar words
   "Chinese is a tonic language";
   - tonal
    
4. (used of syllables) bearing the principle stress, usually accompanied by a change in pitch
   "a tonic syllable carries the main stress in a word";
   - accented
    
5. Relating to or being the keynote of a major or minor scale
   "tonic harmony"

Derived forms: tonics

See also: invigorating, tonal

Type of: med [informal], medicament, medication, medicinal drug, medicine, musical note, note, soft drink, tone

Part of: gin and tonic

Encyclopedia: Tonic